20
18
RE
LE
AS
E
THE UNDERSTATEMENT OF
EXISTENTIAL CLIMATE RISK
BY DAVID SPRATT & IAN DUNLOP | FOREWORD BY HANS JOACHIM SCHELLNHUBER
BREAKTHROUGHONLINE.ORG.AU
Published by Breakthrough - National Centre for Climate Restoration, Melbourne, Australia. First published September 2017. Revised and updated August 2018.
CONTENTS
FOREWORD 02
INTRODUCTION 04
RISK UNDERSTATEMENT
EXCESSIVE CAUTION 08
THINKING THE UNTHINKABLE 09
THE UNDERESTIMATION OF RISK 10
EXISTENTIAL RISK TO HUMAN CIVILISATION 13
PUBLIC SECTOR DUTY OF CARE ON CLIMATE RISK 15
SCIENTIFIC UNDERSTATEMENT
CLIMATE MODELS 18
TIPPING POINTS 21
CLIMATE SENSITIVITY 22
CARBON BUDGETS 24
PERMAFROST AND THE CARBON CYCLE 25
ARCTIC SEA ICE 27
POLAR ICE-MASS LOSS 28
SEA-LEVEL RISE 30
POLITICAL UNDERSTATEMENT
POLITICISATION 34
GOALS ABANDONED 36
A FAILURE OF IMAGINATION 38
ADDRESSING EXISTENTIAL CLIMATE RISK 39
SUMMARY 40
What Lies Beneath 2
FOREWORD
What Lies Beneath is an important report. It does not
deliver new facts and figures, but instead provides
a new perspective on the existential risks associated
with anthropogenic global warming.
It is the critical overview of well-informed
intellectuals who sit outside the climate-science
community which has developed over the last fifty
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years. All such expert communities are prone to
what the French call deformation professionelle and the
German betriebsblindheit.
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Expressed in plain English, experts tend to establish
a peer world-view which becomes ever more rigid
and focussed. Yet the crucial insights regarding
the issue in question may lurk at the fringes, as
BY HANS JOACHIM SCHELLNHUBER this report suggests. This is particularly true when
Hans Joachim Schellnhuber is a professor of theoretical the issue is the very survival of our civilisation,
physics specialising in complex systems and nonlinearity, where conventional means of analysis may become
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founding director of the Potsdam Institute for Climate useless.
Impact Research (1992-2018) and former chair of the This dilemma notwithstanding, the
German Advisory Council on Global Change. He is a Intergovernmental Panel on Climate Change
senior climate advisor to the European Union, the German (IPCC) bravely perseveres with its attempts to assess
Chancellor and Pope Francis. the multiple cause-and-effect relationships which
comprise the climate problem. After delivering
five fully-fledged assessment reports, it is hardly
surprising that a trend towards “erring on the side
of least drama” has emerged.
AF
There are many reasons, both subtle and mundane.
Let me highlight just one of each.
Firstly, the IPCC is stricken with the Probability
Obsession. Ever since statistics was established in
the16th century, scientists have tried to capture the
complex, stochastic behaviour of a given non-
DR
trivial object (such as a roulette wheel) by repeating
the same experiment on that object many, many
times. If there was a set of well-defined outcomes
(such as the ball ending on the red or black of the
wheel), then the probability of a specific outcome
was simply the number of experiments delivering
that outcome divided by the total number of
experiments.
This sounds reasonable, but can we even imagine
applying that approach to global warming? Strictly
speaking, we would have to redo the Industrial
Revolution and the greenhouse-gas emissions it
triggered a thousand times or so, always starting
with the Earth system in its 1750 pre-industrial
state.
What Lies Beneath 3
Then calculate the averaged observed outcome of In turn, this means that scientific progress is often
that planetary experiment in terms of mean driven from the periphery, or occasionally, by
surface-temperature rise, global biological eminent personalities whose seniority is beyond
productivity, total number of climate refugees, and doubt. This does not at all imply that hypotheses
many other variables. This is a nonsensical notion. need not be vindicated in due course, but out-of-
the-box thinking is vital given the unprecedented
Of course, climate scientists are not trying to treat
climate risks which now confront human
the Earth like a roulette wheel, yet the statistical
civilisation.
approach keeps on creeping into the assessments.
How many times did the thermohaline circulation In conclusion, one should not be overly critical of
collapse under comparable conditions in the the IPCC, since the scientists involved are doing
planetary past? How often did the Pacific enter a what scientists are expected to do, to the very best
permanent El Niño state in the Holocene? And so of their ability in difficult circumstances.
on. These are valuable questions that can generate But climate change is now reaching the end-game,
precious scientific insights. where very soon humanity must choose between
But we must never forget that we are in a unique taking unprecedented action, or accepting that it
situation with no precise historic analogue. The has been left too late and bear the consequences.
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level of greenhouse gases in the atmosphere is now Therefore, it is all the more important to listen to
greater, and the Earth warmer, than human beings non-mainstream voices who do understand the
have ever experienced. And there are almost eight issues and are less hesitant to cry wolf.
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billion of us now living on this planet. Unfortunately for us, the wolf may already be in
So calculating probabilities makes little sense in the house.
the most critical instances, such as the methane-
release dynamics in thawing permafrost areas or
the potential failing of entire states in the climate
crisis. Rather, we should identify possibilities, that is,
potential developments in the planetary make-up
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that are consistent with the initial and boundary
conditions, the processes and the drivers we know.
This is akin to scenario planning, now being
proposed for assessing climate risks in the corporate
sector, where the consequences of a number of
future possibilities, including those which may
seem highly unlikely, but have major consequences,
are evaluated. This way one can overcome the
probability obsession that not only fantasizes about
AF
the replicability of the singular, but also favours the
familiar over the unknown and unexpected.
As an extreme example, the fact that our world
has never been destroyed previously would
conventionally assign probability zero to such
an event. But this only holds true under steady-
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state assumptions, which are practically never
warranted.
Secondly, there is the Devil’s Advocate Reward. In the
magnificent tradition of the Enlightenment, which
shattered so many myths of the ancient regimes,
scientists are trained to be sceptical about every
proposition which cannot be directly verified by
empirical evidence or derived from first principles
(such as the invariability of the speed of light).
So, if a researcher comes up with an entirely
new thought, experts tend to reflexively dismiss
it as “speculative”, which is effectively a death
warrant in the academic world. Whereas those who
criticize the idea will be applauded, rewarded and
promoted! This phenomenon is evident in every
seminar, colloquium or learned-society assembly.
What Lies Beneath 4
INTRODUCTION
Three decades ago, when serious debate on A one-in-two or one-in-three chance of missing
human-induced climate change began at the global a goal is normalised as reasonable. Moral hazard
level, a great deal of statesmanship was on display. permeates official thinking, in that there is an
There was a preparedness to recognise that this incentive to ignore the risks in the interests of
was an issue transcending nation states, ideologies political expediency.
and political parties which had to be addressed Climate policymaking for years has been
proactively in the long-term interests of humanity cognitively dissonant, “a flagrant violation of
as a whole. This was the case even though the reality”. So it is unsurprising that there is a lack
existential nature of the risk it posed was far less of understanding amongst the public and elites
clear cut than it is today. of the full measure of the climate challenge. Yet
As global institutions, such as the United Nations most Australians sense where we are heading:
Framework Convention on Climate Change three-quarters of Australians see climate change
(UNFCCC) which was established at the Rio Earth as catastrophic risk,2 and half see our way of life
Summit in 1992, were developed to take up this ending within the next 100 years.3
challenge, and the extent of change this would Politics and policymaking have norms: rules
demand of the fossil-fuel-dominated world order and practices, assumptions and boundaries,
became clearer, the forces of resistance began to that constrain and shape them. In recent years,
mobilise. Today, as a consequence, and despite the the previous norms of statesmanship and long-
diplomatic triumph of the 2015 Paris Agreement, the term thinking have disappeared, replaced by an
debate around climate change policy has never obsession with short-term political and commercial
been more dysfunctional, indeed Orwellian. advantage. Climate policymaking is no exception.
In his book 1984, George Orwell describes a Since 1992, short-term economic interest has
double-think totalitarian state where most of the trumped environmental and future human needs.
population accepts “the most flagrant violations The world today emits 50% more carbon dioxide
of reality, because they never fully grasped the (CO2) from the consumption of energy than it did
enormity of what was demanded of them, 25 years ago, and the global economy has more
and were not sufficiently interested in public than doubled in size. The UNFCCC strives “to
events to notice what was happening. By lack of enable economic development to proceed in a
understanding they remained sane.”1 sustainable manner”, but every year humanity’s
Orwell could have been writing about climate ecological footprint becomes larger and less
change and policymaking. International sustainable. Humanity now requires the biophysical
agreements talk of limiting global warming to capacity of 1.7 Earths annually as it rapidly chews
1.5–2 degrees Celsius (°C), but in reality they set up natural capital.
the world on a path of 3–5°C of warming. Goals A fast, emergency-scale transition to a post-fossil
are reaffirmed, only to be abandoned. Coal is fuel world is absolutely necessary to address climate
“clean”. Just 1°C of warming is already dangerous, change. But this is excluded from consideration
but this cannot be admitted. The planetary future by policymakers because it is considered to be too
is hostage to myopic national self-interest. Action disruptive. The orthodoxy is that there is time for
is delayed on the assumption that as yet unproven an orderly economic transition within the current
technologies will save the day, decades hence. The short-termist political paradigm. Discussion of
risks are existential, but it is “alarmist” to say so. what would be safe –– less warming than we
presently experience –– is non-existent. And so we
have a policy failure of epic proportions.
1 Orwell, G 1949, Nineteen Eighty-Four. A Novel, Secker and Warburg, London.
2 CommunicateResearch 2017, ‘Global Challenges Foundation global risks survey’, ComRes, 24 May 2017, <http://www.comresglobal.com/polls/global-
challenges-foundation-global-risks-survey>.
3 Randle, MJ & Eckersley, R 2015, ‘Public perceptions of future threats to humanity and different societal responses: a cross-national study’, Futures,
vol. 72, pp. 4-16.
What Lies Beneath 5
Policymakers, in their magical thinking, imagine These limitations are understandable, and
a mitigation path of gradual change to be arguably were not of overriding importance in
constructed over many decades in a growing, the early period of the IPCC. However, as time
prosperous world. The world not imagined is has progressed, it is now clear that the risks posed
the one that now exists: of looming financial by climate change are far greater than previously
instability; of a global crisis of political legitimacy anticipated. We have moved out of the twilight
and “fake news”; of a sustainability crisis that period of much talk, but relatively limited climate
extends far beyond climate change to include all impacts, into the harsh light of physically-evident
the fundamentals of human existence and most existential threats. Climate change is now turning
significant planetary boundaries (soils, potable nasty, as we have witnessed recently in the North
water, oceans, the atmosphere, biodiversity, and so America, East and South Asia, the Middle East
on); and of severe global energy-sector dislocation. and Europe, with record-breaking heatwaves
In anticipation of the upheaval that climate change and wildfires, more intense flooding and more
would impose upon the global order, the IPCC was damaging hurricanes.
established by the United Nations (UN) in 1988, The distinction between climate science and risk
charged with regularly assessing the global consensus is the critical issue, for the two are not the same.
on climate science as a basis for policymaking. The Scientific reticence — a reluctance to spell out
IPCC Assessment Reports (AR), produced every five-to- the full risk implications of climate science in the
eight years, play a large part in the public framing of absence of perfect information — has become
the climate narrative: new reports are a global media a major problem. Whilst this is understandable,
event. AR5 was produced in 2013-14, with AR6 due particularly when scientists are continually
in 2022. The IPCC has done critical, indispensable criticised by denialists and political apparatchiks for
work of the highest standard in pulling together speaking out, it is extremely dangerous given the
a periodic consensus of what must be the most fat-tail risks of climate change. Waiting for perfect
exhaustive scientific investigation in world history. information, as we are continually urged to do by
It does not carry out its own research, but reviews political and economic elites, means it will be too
and collates peer-reviewed material from across the late to act. Time is not on our side. Sensible risk
spectrum of this incredibly complex area, identifying management addresses risk in time to prevent it
key issues and trends for policymaker consideration. happening, and that time is now.
However, the IPCC process suffers from all the Irreversible, adverse climate change on the global
dangers of consensus-building in such a wide- scale now occurring is an existential risk to human
ranging and complex arena. For example, IPCC civilisation. Many of the world’s top climate
reports, of necessity, do not always contain the latest scientists — Kevin Anderson, James Hansen,
available information. Consensus-building can lead Michael E. Mann, Michael Oppenheimer, Naomi
to “least drama”, lowest-common-denominator Oreskes, Stefan Rahmstorf, Eric Rignot, Hans
outcomes, which overlook critical issues. This Joachim Schellnhuber, Kevin Trenberth and others
is particularly the case with the “fat-tails” of — who are quoted in this report well understand
probability distributions, that is, the high-impact but these implications and are forthright about their
lower-probability events where scientific knowledge findings, where we are heading, and the limitations
is more limited. of IPCC reports.
Vested-interest pressure is acute in all directions; This report seeks to alert the wider community and
climate denialists accuse the IPCC of alarmism, business and political leaders to these limitations
whereas many climate action proponents consider and urges changes to the IPCC approach, to the
the IPCC to be far too conservative. To cap it all, wider UNFCCC negotiations, and to national
the IPCC conclusions are subject to intense political policymaking. It is clear that existing processes will
oversight before being released, which historically not deliver the transformation to a carbon-negative
has had the effect of substantially watering-down world in the limited time now available.
sound scientific findings. We urgently require a reframing of scientific
research within an existential risk-management
framework. This requires special precautions that go
well beyond conventional risk management. Like an
iceberg, there is great danger in “what lies beneath”.
What Lies Beneath 6
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“We are climbing rapidly out of mankind's
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safe zone into new territory, and we have
no idea if we can live in it."
Prof. Robert Corell, 2007
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What Lies Beneath 7
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UNDERSTATEMENT
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What Lies Beneath 8
EXCESSIVE CAUTION
A 2013 study by Prof. Naomi Oreskes and Ten years after his 2006 climate report to the
fellow researchers examined a number of past UK government, Sir Nicholas Stern reflected
predictions made by climate scientists. They found that “science is telling us that impacts of global
that scientists have been “conservative in their warming — like ice sheet and glacier melting
projections of the impacts of climate change” and — are now happening much more quickly than
that “at least some of the key attributes of global we anticipated”.7 In 2013, he said that “Looking
warming from increased atmospheric greenhouse back, I underestimated the risks… Some of the
gases have been under-predicted, particularly effects are coming through more quickly than we
in IPCC assessments of the physical science”. thought then.”8
They concluded that climate scientists are not A recent study of climate scientists found “a
biased toward alarmism but rather the reverse of community which still identified strongly with an
“erring on the side of least drama, whose causes idealised picture of scientific rationality, in which
may include adherence to the scientific norms the job of scientists is to get on with their research
of restraint, objectivity, skepticism, rationality, quietly and dispassionately”.9 The study said most
dispassion, and moderation”. This may cause climate scientists are resistant to participation in
scientists “to underpredict or downplay future public/policy engagement, leaving this task to a
climate changes”.4 minority who are attacked by the media and even
This tallies with the view of economist Prof. Ross by their own colleagues.
Garnaut, who in 2011 reflected on his experience Kevin Trenberth, head of climate analysis at the
in presenting two climate reports to the Australian US National Center for Atmospheric Research and
Government. Garnaut questioned whether a lead author of key sections of the 2001 and 2007
climate research had a conservative “systematic IPCC reports, says: “We’re underestimating the
bias” due to “scholarly reticence”. He pointed fact that climate change is rearing its head… and
to a pattern across diverse intellectual fields of we’re underestimating the role of humans, and this
research predictions being “not too far away from means we’re underestimating what it means for the
the mainstream” expectations and observed that in future and what we should be planning for.”10
the climate field that this “has been associated with
Prof. Michael E. Mann of Pennsylvania State
understatement of the risks”.5
University says the IPCC’s 2012 report on climate
As far back as 2007, then NASA climate science extremes missed an opportunity to provide
chief Prof. James Hansen suggested that scientific politicians with a clear picture of the extent of
reticence hinders communication with the the climate crisis: “Many scientists felt that report
public about the dangers of global warming and erred by underplaying the degree of confidence
potentially large sea-level rises. More recently he in the linkage between climate change and certain
wrote that “the affliction is widespread and severe. types of severe weather, including heat wave
Unless recognized, it may severely diminish our severity, heavy precipitation and drought, and
chances of averting dangerous climate change.”6 hurricane intensity.”11
4 Brysse, K, Oreskes, N, O’Reilly, J & Oppenheimer, M 2013, ‘Climate change prediction: Erring on the side of least drama?’, Global Environmental Change,
vol. 23, no. 1, pp. 327-337.
5 Garnaut, R 2011, Update Paper 5: The science of climate change, Garnaut Climate Change Review Update, Canberra, pp. 53-55.
6 Hansen, J 2007, ‘Scientific reticence and sea level rise’, Environmental Research Letters, vol. 2, no. 2, 024002.
7 McKee, R 2016, ‘Nicholas Stern: cost of global warming “is worse than I feared”’, The Guardian, 6 November 2016.
8 Stewart, H & Elliott, L 2013, ‘Nicholas Stern: “I got it wrong on climate change – it’s far, far worse”’, The Guardian, 27 January 2013.
9 Hoggett, P & Randall, R 2016, ‘Socially constructed silence? Protecting policymakers from the unthinkable’, Transformation, 6 June 2016, <https://
www.opendemocracy.net/transformation/paul-hoggett-rosemary-randall/socially-constructed-silence-protecting-policymakers-fr>.
10 Scherer, G 2012a, ‘How the IPCC underestimated climate change’, Scientific American, 6 December 2012.
11 Scherer, G 2012b, ‘Climate science predictions prove too conservative’, Scientific American, 6 December 2012.
What Lies Beneath 9
Prof. Kevin Anderson of the University of Anderson says it is incumbent on the scientific
Manchester says there is “an endemic bias community to communicate research clearly
prevalent amongst many of those building and candidly to those delivering on the climate
emission scenarios to underplay the scale of the goals established by civil society, and “to draw
2°C challenge. In several respects, the modelling attention to inconsistencies, misunderstandings and
community is actually self-censoring its research deliberate abuse of the scientific research. It is not
(focus) to conform to the dominant political and our job to be politically expedient with our analysis
economic paradigm…”12 or to curry favour with our funders. Whether our
A good example is the 1.5°C goal agreed to at the conclusions are liked or not is irrelevant.”1314
Paris December 2015 climate policy conference.
IPCC assessment reports until that time (and in
conformity with the dominant political paradigm)
had not devoted any significant attention to 1.5°C
emission-reduction scenarios or 1.5°C impacts, and
the Paris delegates had to request the IPCC to do so
as a matter of urgency. This is a clear case of politics
driving the science research agenda. Research needs
money, and too often money is allocated according
to the political priorities of the day.
THINKING THE UNTHINKABLE
Successful risk management requires thinking • The rate and scale of change is much faster
“outside the box” to avoid a failure of imagination, than most are even prepared to concede
but this is a skill rarely found at the senior levels of or respond to. At the highest board and
government and global corporations. C-suite levels, executives and their public
A 2016 report, Thinking the unthinkable, based on service equivalents confess to often being
interviews with top leaders around the world, found overwhelmed.
that: “A proliferation of ‘unthinkable’ events… • Time is at such a premium that the pressing
has revealed a new fragility at the highest levels of need to think, reflect and contemplate in the
corporate and public service leaderships. Their ways required by the new “unthinkables” is
ability to spot, identify and handle unexpected, largely marginalised.
non-normative events is… perilously inadequate at Often blind eyes were turned, either because of
critical moments.”13 a lack of will to believe the signs, or an active
The report findings are highly relevant to preference to deny and then not to engage.
understanding the failure of climate policymaking, While the phrase, “Thinking the unthinkable”,
and the failure to adequately communicate and has an attractive rhetorical symmetry, a more
think about the full range of potential climate appropriate and accurate phrase might in many
warming risks. It found that: cases therefore be “Thinking the unpalatable”.
• The emerging picture is both scary and of These deficiencies are clearly evident at the upper
great concern. Remarkably, there remains levels of climate policymaking, nationally and
a deep reluctance, or what might be called globally. They must be corrected as a matter of
“executive myopia” amongst top leaders in extreme urgency.
both the public and private sectors, to see
and contemplate even the possibility that
“unthinkables” might happen, let alone how to
handle them.
12 Anderson, K 2016, ‘Going beyond ‘dangerous’ climate change’, LSE presentation, 4 February 2016, <http://www.lse.ac.uk/newsAndMedia/
videoAndAudio/channels/publicLecturesAndEvents/player.aspx?id=3363>.
13 Anderson, K 2015, ‘Duality in climate science’, Nature Geoscience, vol. 8, pp. 898–900.
14 Gowing, N & Langdon, C 2016, Thinking the Unthinkable: A new imperative for leadership in the digital age, Chartered Institute of Management Accountants,
London.
What Lies Beneath 10
THE UNDERESTIMATION
OF RISK
There are fundamental challenges in Former senior coal fossil fuel executive and
understanding and communicating risks. These government advisor, Ian Dunlop, notes that
include “the importance of complex interactions “dangerous impacts from the underlying (warming)
in shaping risks, the need for rigorous expert trend have also manifested far faster and more
judgment in evaluating risks, and the centrality of extensively than global leaders and negotiators are
values, perceptions, and goals in determining both prepared to recognise”.19
risks and responses”.15 Researchers say it is important to carry out analyses
IPCC reports have underplayed high-end “to identify what risky outcomes are possible —
possibilities and failed to assess risks in a balanced cannot be ruled out — starting with the biggest
manner. The failure to fully account for potential ones. In such analyses, it is useful to distinguish
future changes to permafrost (frozen carbon stores between two questions: ‘What is most likely to
on land and under the seabed) and other carbon- happen?’ and ‘How bad could things get?’”20
cycle feedbacks is just one example. In looking at how to reframe climate change
Dr Barrie Pittock, a former leader of the Climate assessments around risk, it is important to:
Impact Group in CSIRO, wrote in 2006 that “ … deal adequately with low-probability, high-
“until now many scientists may have consciously consequence outcomes, which can dominate
or unconsciously downplayed the more extreme calculations of total risk, and are thus worthy
possibilities at the high end of the uncertainty range, of special attention. Without such efforts, we
in an attempt to appear moderate and ‘responsible’ court the kinds of ‘failures of imagination’
(that is, to avoid scaring people). However, true that can prove so costly across risk domains.
responsibility is to provide evidence of what must Traditional climate assessments have focused
be avoided: to define, quantify, and warn against primarily on areas where the science is mature
possible dangerous or unacceptable outcomes.”16 and uncertainties well characterized. For
The situation has not improved. Sir Nicholas example, in the IPCC lexicon, future outcomes
Stern said of the IPCC’s Fifth Assessment Report: are considered ‘unlikely’ if they lie outside the
“Essentially it reported on a body of literature that central 67% of the probability distribution. For
had systematically and grossly underestimated the many types of risk assessment, however, a 33%
risks [and costs] of unmanaged climate change.”17 chance of occurrence would be very high; a 1%
or 0.1% chance (or even lower probabilities)
Prof. Ross Garnaut has also pointed to the
would be more typical thresholds.”21
“understatement of the risks”, in that we seem
to be playing scientific catch-up, as reality is They emphasise that “the envelope of possibilities”,
consistently on the most pessimistic boundary that is, the full range of possibilities for which
of previous projections. The Australian Climate one must be prepared, is often more important
Council reported in 2015: “Changes in the climate than the most likely future outcome, especially
system are occurring more rapidly than previously when the range of outcomes includes those that
projected, with larger and more damaging are particularly severe. They conclude that the
impacts now observed at lower temperatures than “application of scientific rather than risk-based
previously estimated.”18 Such a situation is not a norms in communicating climate change uncertainty
satisfactory basis on which to plan our future. has also made it easier for policymakers and other
actors to downplay relevant future climate risks”.22
15 Mach, K, Mastrandrea, MD, Bilir, TE & Field, CB 2015, ‘Understanding and responding to danger from climate change: the role of key risks in the
IPCC AR5’, Climatic Change, vol. 136, pp. 427-444.
16 Pittock, AB 2006, ‘Are scientists underestimating climate change?’, EOS, vol. 87, no. 34, pp. 340-41.
17 Stern, N 2016, ‘Economics: Current climate models are grossly misleading’, Nature, vol. 530, pp. 407-409.
18 Steffen, W, Hughes, L & Pearce, A 2015, Climate Change: Growing risks, critical choices, Climate Council, Sydney.
19 Dunlop, I 2016, Foreword to Spratt, D 2016, Climate Reality Check, Breakthrough, Melbourne.
20 Weaver, C, Moss, R, Ebi, K, Gleick, P, Stern, P, Tebaldi, C, Wilson, R & Arvai, J 2017, ‘Reframing climate change assessments around risk:
recommendations for the US National Climate Assessment’, Environmental Research Letters, vol. 12, no. 8, 080201.
21 ibid.
22 ibid.
What Lies Beneath 11
A prudent risk-management approach means a “ Let us consider… the prospects for warming well
tough and objective look at the real risks to which in excess of what we might term “dangerous”
we are exposed, especially those high-end events (typically considered to be at least 2°C warming
whose consequences may be damaging beyond of the planet). How likely, for example, are we to
quantification, and which human civilization as we experience a catastrophic 6°C warming of the
know it would be lucky to survive. It is important to globe, if we allow greenhouse gas concentrations
understand the potential of, and plan for, the worst to reach double their pre-industrial levels
that can happen, and be pleasantly surprised if it (something we’re on course to do by the middle
doesn’t. Focusing on middle-of-the-road outcomes, of this century given business-as-usual burning
and ignoring the high-end possibilities, may result of fossil fuels)? Well, the mean or average
in an unexpected catastrophic event that we could, warming that is predicted by models in that
and should, have seen coming. scenario is about 3°C, and the standard deviation
Prof. Robert Socolow of Princeton University about 1.5°C. So the positive tail, defined as the
says the IPCC “should communicate fully +2 sigma limit, is about 6°C of warming. As
what the science community does and does not shown by Wagner & Weitzman [Figure 1(b)], the
understand about high consequence outcomes.The likelihood of exceeding that amount of warming
policymaking community needs information about isn’t 2% as we would expect for a bell-curve
both probable and improbable outcomes.”23 distribution. It’s closer to 10%!
In fact, it’s actually even worse than that when
Integral to this approach is the issue of lower-
we consider the associated risk. Risk is defined as
probability, high-impact consequences known as
the product of the likelihood and consequence
fat-tail risks, in which the likelihood of very large
of an outcome. We just saw that the likelihood
impacts is actually greater than we would expect
of warming is described by a heavy-tailed
under typical statistical assumptions. A normal
distribution, with a higher likelihood of far-
distribution, with the appearance of a bell curve,
greater-than-average amounts of warming
is symmetric in probabilities of low outcomes (left
than we would expect given typical statistical
of curve) and high outcomes (right of curve) as
assumptions. This is further compounded by
per Figure 1(a). But, as Prof. Michael E. Mann
the fact that the damages caused by climate
explains, “global warming instead displays what
change — i.e. the consequence — also increases
we call a ‘heavy-tailed’ or ‘fat-tailed’ distribution,
dramatically with warming. That further
there is more area under the far right extreme
increases the associated risk.
of the curve than we would expect for a normal
With additional warming comes the increased
distribution, a greater likelihood of warming that
likelihood that we exceed certain tipping points,
is well in excess of the average amount of warming
like the melting of large parts of the Greenland
predicted by climate models,”24 as per Figure 1(b).
and Antarctic ice sheet and the associated massive
In Climate Shock: The Economic Consequences of a Hotter rise in sea level that would produce… Uncertainty
Planet, economists Gernot Wagner and Martin is not our friend when it comes to the prospects for
Weitzman explore the implications of this fat-tail dangerous climate change.”26
distribution for climate policy, and “why we face
an existential threat in human-caused climate
change”.25 Mann explains:
a) b)
40%
35%
30%
25%
20%
34.1% 34.1% 15%
2.1% 2.1% 10%
0.1% 0.1%
5%
13.6% 13.6% >10%
0%
-3σ -2σ -1σ μ 1σ 2σ 3σ 0ºC 1ºC 2ºC 3ºC 4ºC 5ºC 6ºC 7ºC 8ºC 9ºC 10ºC
Eventual global average warming based on passing 700 ppm CO2e
Figure 1: Normal and “fat tail” probability distributions. (a) Normal probability distribution, and (b) an estimate of the likelihood of warming due to a doubling
of greenhouse gas concentrations exhibiting a “fat tail” distribution (Credit: Wagner & Weitzman 2015, Climate Shock: The Economic Consequences of a Hotter Planet).
23 Socolow, R. 2011, ‘High-consequence outcomes and internal disagreements: tell us more, please’, Climatic Change, vol. 108, pp. 775-790.
24 Mann, M 2016, ‘The ‘fat tail’ of climate change risk’, Huffington Post, 11 September 2016.
25 Ibid.
26 Ibid.
What Lies Beneath 12
As Mann notes, risk is defined as the product of the “When all the new knowledge that
likelihood and consequence of an outcome. This is
illustrated in Figure 2, which although applied to the challenges the old is on the more
question of climate sensitivity (see discussion on worrying side, one worries about
whether the asymmetry reflects some
pp. 22-23), has general applicability. The likelihood
of a high-end outcome may be relatively low (right
side of curve in (a)), but impacts increase at the high- systematic bias… I have come to wonder
end (b), showing the high risk of very unlikely events
(c). whether the reason why most of the new
IPCC reports have not given attention to fat- knowledge confirms the established
tail risk analysis, in part because the reports are
compiled using a consensus method, as discussed science or changes it for the worse is
above. Prof. Stefan Rahmstorf of Potsdam scholarly reticence.”
University says that:
Prof. Ross Garnaut, 2011
“ The magnitude of the fat-tail risks of global
warming is not widely appreciated and must
be discussed more. For over two decades I have
argued that the risk of a collapse of the Atlantic
meridional overturning circulation (AMOC) in
this century is perhaps five per cent or so, but
that this is far too great a risk to take, given what
is at stake. Nobody would board an aircraft with
a five per cent risk of crashing.”27
He adds that: “Defeatism and doomerism is not the
same as an accurate, sincere and sober discussion
of worst-case risks. We don’t need the former,
we do need the latter.” It should be noted that
Rahmstorf was one of the authors of research
released in April 2018 showing that, in fact, there
has already been a 15% slowdown in the AMOC
since the mid-twentieth century.28
a) Likelihood b) Impact c) Risk
X =
Very
Likely
Unlikely
Climate sensitivity [K] Climate sensitivity [K] Climate sensitivity [K]
Figure 2: Schema of climate-related risk. (a) Event likelihood and (b) Impacts produce (c) Risk. Lower likelihood
events at the high end of the probability distribution have the highest risk (Credit: RT Sutton/E Hawkins).
27 Rahmstorf, S, pers. comm., 8 August 2017.
28 Caesar, L, Rahmstorf, S, Robinson, A, Feulner, G. & Saba, V 2018, “Observed fingerprint of a weakening Atlantic Ocean overturning circulation’,
Nature, vol. 556, pp. 191-192.
What Lies Beneath 13
EXISTENTIAL RISK TO
HUMAN CIVILISATION
In 2016, the World Economic Forum survey Yet 3°C of warming already constitutes an
of the most impactful risks for the years ahead existential risk. A 2007 study by two US national
elevated the failure of climate change mitigation security think-tanks concluded that 3°C of warming
and adaptation to the top of the list, ahead of and a 0.5 metre sea-level rise would likely lead to
weapons of mass destruction, ranking second, and “outright chaos” and “nuclear war is possible”,
water crises, ranking third. By 2018, following a emphasising how “massive non-linear events
year characterised by high-impact hurricanes and in the global environment give rise to massive
extreme temperatures, extreme-weather events nonlinear societal events”.33 The Global Challenges
were seen as the single most prominent risk. As Foundation (GCF) explains what could happen:
the survey noted: “We have been pushing our “ If climate change was to reach 3°C, most of
planet to the brink and the damage is becoming Bangladesh and Florida would drown, while
increasingly clear.”29 major coastal cities — Shanghai, Lagos,
Climate change is an existential risk to human Mumbai — would be swamped, likely creating
civilisation: that is, an adverse outcome that would large flows of climate refugees. Most regions
either annihilate intelligent life or permanently and in the world would see a significant drop in
drastically curtail its potential. food production and increasing numbers of
Temperature rises that are now in prospect, after extreme weather events, whether heat waves,
the Paris Agreement, are in the range of 3–5°C. At floods or storms. This likely scenario for a 3°C
present, the Paris Agreement voluntary emission rise does not take into account the considerable
reduction commitments, if implemented, would risk that self-reinforcing feedback loops set in
result in planetary warming of 3.4°C by 2100,30 when a certain threshold is reached, leading
without taking into account “long-term” carbon- to an ever increasing rise in temperature.
cycle feedbacks. With a higher climate sensitivity Potential thresholds include the melting of the
figure of 4.5°C, for example, which would Arctic permafrost releasing methane into the
account for such feedbacks, the Paris path would atmosphere, forest dieback releasing the carbon
result in around 5°C of warming, according to currently stored in the Amazon and boreal
a MIT study.31 A study by Schroder Investment forests, or the melting of polar ice caps that
Management published in June 2017 found — after would no longer reflect away light and heat
taking into account indicators across a wide range from the sun.”34
of the political, financial, energy and regulatory
sectors — the average temperature increase implied
for the Paris Agreement across all sectors was 4.1°C.32
29 World Economic Forum, 2018, The Global Risks Report 2018: 13th Edition, World Economic Forum, Geneva.
30 Climate Action Tracker 2017, ‘Improvement in warming outlook as India and China move ahead, but Paris Agreement gap still looms large”, 13
November 2017, <http://climateactiontracker.org/publications/briefing/288/Improvement-in-warming-outlook-as-India-and-China-move-ahead-but-
Paris-Agreement-gap-still-looms-large.htm>.
31 Reilly, J, Paltsev, S, Monier, E, Chen, H, Sokolov, A, Huang, J, Ejaz, Q , Scott, J, Morris, J & Schlosser, A 2015, Energy and Climate Outlook: Perspectives from
2015, MIT Program on the Science and Policy of Global Change, Cambridge MA.
32 Schroder Investment Management 2017, Climate change: calibrating the thermometer, Schroders Investment Management, London.
33 Campbell, K, Gulledge, J, McNeill, JR, Podesta, J, Ogden, P, Fuerth, L, Woolsley, J, Lennon, A, Smith, J, Weitz, R & Mix, D 2007, The Age of
Consequences: The foreign policy and national security implications of global climate change, Centre for Strategic and International Studies & Centre for New
American Security, Washington.
34 Global Challenges Foundation 2017, Global Catastrophic Risks 2017, Global Challenges Foundation, Stockholm.
What Lies Beneath 14
Warming of 4°C or more could reduce the global a high likelihood of human civilization coming to
human population by 80% or 90%,35 and the an end.”40 84% of 8000 people in eight countries
World Bank reports “there is no certainty that surveyed for the Foundation considered climate
adaptation to a 4°C world is possible”.36 Prof. change a “global catastrophic risk”.41
Kevin Anderson says a 4°C future “is incompatible Existential risk may arise from a fast rate of
with an organized global community, is likely to be system change, since the capacity to adapt, in
beyond ‘adaptation’, is devastating to the majority both the natural and human worlds, is inversely
of ecosystems, and has a high probability of not proportional to the pace of change, amongst other
being stable”.37 This is a commonly-held sentiment factors. In 2004, researchers reported on the rate
amongst climate scientists. A recent study by the of warming as a driver of extinction.42 Given we
European Commission’s Joint Research Centre are now on a 3–5°C warming path this century,
found that if the global temperature rose 4°C, then their findings are instructive:
extreme heatwaves with “apparent temperatures”
• If the rate of change is 0.3°C per decade (3°C
peaking at over 55°C will begin to regularly affect
per century), 15% of ecosystems will not be able
many densely populated parts of the world, forcing
to adapt.
much activity in the modern industrial world to
stop.38 (“Apparent temperatures” refers to the Heat • If the rate should exceed 0.4°C per decade,
Index, which quantifies the combined effect of heat all ecosystems will be quickly destroyed,
and humidity to provide people with a means of opportunistic species will dominate, and the
avoiding dangerous conditions.) breakdown of biological material will lead to
even greater emissions of CO2.
In 2017, one of the first research papers to focus
explicitly on existential climate risks proposed At 4°C of warming “the limits for adaptation
that “mitigation goals be set in terms of climate for natural systems would largely be exceeded
risk category instead of a temperature threshold”, throughout the world”.43 Ecological breakdown of
and established a “dangerous” risk category of this scale would ensure an existential human crisis.
warming greater than 1.5°C, and a “catastrophic” By slow degrees, these existential risks are being
category for warming of 3°C or more. The authors recognised. In May 2018, an inquiry by the
focussed on the impacts on the world’s poorest Australian Senate into national security and global
three billion people, on health and heat stress, and warming recognised “climate change as a current
the impacts of climate extremes on such people and existential national security risk… defined as
with limited adaptation resources. They found ‘one that threatens the premature extinction of
that a 2°C warming “would double the land area Earth-originating intelligent life or the permanent
subject to deadly heat and expose 48% of the and drastic destruction of its potential for desirable
population (to deadly heat). A 4°C warming by future development’”.44 In April 2018, the
2100 would subject 47% of the land area and Intelligence on European Pensions and Institutional
almost 74% of the world population to deadly Investment think-tank warned business leaders
heat, which could pose existential risks to humans that “climate change is an existential risk whose
and mammals alike unless massive adaptation elimination must become a corporate objective”.45
measures are implemented.”39 However the most recent IPCC Assessment Report
A 2017 survey of global catastrophic risks by did not consider the issue. Whilst the term “risk
the Global Challenges Foundation found that: management” appears in the 2014 IPCC Synthesis
“In high-end [climate] scenarios, the scale of Report fourteen times, the terms “existential” and
destruction is beyond our capacity to model, with “catastrophic” do not appear.
35 Anderson, K 2011, ‘Going beyond dangerous climate change: Exploring the void between rhetoric and reality in reducing carbon emissions’, LSE
presentation, 11 July 2011.
36 World Bank 2012, Turn Down the Heat: Why a 4°C warmer world must be avoided, World Bank, New York.
37 Roberts, D 2011 “The brutal logic of climate change”, Grist, 6 December 2011, <https://grist.org/climate-change/2011-12-05-the-brutal-logic-of-
climate-change/>.
38 Ayre, J 2017, ‘Extreme heatwaves with ‘apparent temperatures’ as high as 55° celsius to regularly affect much of world’, Clean Technica, 11 August
2017, <https://cleantechnica.com/2017/08/11/extreme-heatwaves-apparent-temperatures-high-55-celsius-regularly-affect-much-world-4-celsius-
warming-pre-industrial-levels/>.
39 Xu, Y & Ramanathan, V 2017, ‘Well below 2 °C: Mitigation strategies for avoiding dangerous to catastrophic climate changes’, Proceedings of the National
Academy of Sciences, vol. 114, pp. 10315-10323.
40 Global Challenges Foundation 2017, op cit.
41 Goering, L 2017, ‘8 in 10 people now see climate change as a ‘catastrophic risk’ – survey’, Thomson Reuters Foundation, 23 May 2017, <http://news.
trust.org/item/20170523230148-a90de>.
42 Leemans, R, & Eickhout, B 2004, ‘Another reason for concern: regional and global impacts on ecosystems for different levels of climate change’, Global
Environmental Change, vol. 14, pp. 219–228.
43 Warren, R 2011, ‘The role of interactions in a world implementing adaptation and mitigation solutions to climate change’, Philosophical Transactions of the
Royal Society A, vol. 369, pp. 217-241.
44 Commonwealth of Australia 2018, Inquiry into the Implications of climate change for Australia’s national security, Foreign Affairs, Defence and Trade Committee,
Department of the Senate, Parliament House, Canberra.
45 Murray, D & Murtha, A 2018, ‘Climate risk: Running out of time’, Intelligence on European Pensions and Institutional Investment, April 2018,
<https://www.ipe.com/reports/special-reports/thought-leadership/climate-risk-running-out-of-time/10023906.article>.
What Lies Beneath 15
Existential risks require a particular approach Existential risk management requires brutally
to risk management. They are not amenable honest articulation of the risks, opportunities and
to the reactive (learn from failure) approach of the response time frame, the development of new
conventional risk management, and we cannot existential risk-management techniques outside
necessarily rely on the institutions, moral norms, conventional politics, and global leadership and
or social attitudes developed from our experience integrated policy. Since it is not possible to recover
with managing other sorts of risks. Because the from existential risks, “we cannot allow even one
consequences are so severe — perhaps the end of existential disaster to happen; there would be no
global human civilisation as we know it — “even opportunity to learn from experience”,47 but at
for an honest, truth-seeking, and well-intentioned the moment we are facing existential disasters on
investigator it is difficult to think and act rationally several climate fronts, seemingly without being able
in regard to… existential risks”.46 even to articulate that fact.
The failure of both the research community and
the policymaking apparatus to consider, advocate
and/or adopt an existential risk-management
approach is itself a failure of imagination with
catastrophic consequences.
PUBLIC SECTOR DUTY OF CARE ON CLIMATE RISK
Private-sector company directors internationally This duty has a particular sharpness in the new era
are facing legal action and personal liability for of disruption and existential risk that will manifest
having refused to understand, assess and act as a consequence of the global failure, and the
upon climate risk, or for misrepresenting that failure of successive Australian governments, to
risk. Compensation is being sought from carbon rein in global warming.
polluters for damage incurred from climate In these circumstances, our public sector
impacts. Legal opinions suggest similar action in leaders have a number of specific duty-of-
Australia would be firmly based. care responsibilities which at present are being
Such a duty of care extends to the public sector, ignored. Being a climate denier does not absolve
including not only ministers and senior public ministers and parliamentarians of the fiduciary
servants, but regulators and board members of responsibility to set aside personal prejudice and
statutory authorities. As a general principle, officials act in the public interest.
in the public sector should not be held to a lower The Australian Public Service Impartiality
standard of account than employees of publicly Value requires advice given to government to be
listed companies. That duty has already been “apolitical, frank, honest, timely and based on
successfully tested in the courts in The Netherlands. the best available evidence”, but the overriding
The first duty of a government is to protect the impression is that the federal bureaucracy, with
people. A government derives its legitimacy and some notable exceptions, is not treating climate
hence its authority from the people, and so has change with anywhere near the seriousness and
a fiduciary duty to act in accordance with the urgency it demands. Dismal reports such as the
interests of all the people with integrity, fairness December 2017 Review of Climate Change Policy.
and accountability. are a scientifically reticent whitewash of wholly
In the climate arena, this duty has been recognised inadequate and inconsistent policies.
in several quarters, including by Australian It is entirely appropriate, when the political system
Prudential Regulatory Authority Executive fails, for affected parties to take legal action to
Director Geoff Summerhayes and Australian correct such failure.
Securities and Investments Commissioner John
Price.
46 Bostrom, N & Cirkovic, MM 2008, Global Catastrophic Risks, Oxford University Press, Oxford.
47 Op. cit.
What Lies Beneath 16
Y
NL
“We’ve reached a point where we have a crisis, an
emergency, but people don’t know that. ...There’s
TO
a big gap between what’s understood about global
warming by the scientific community and what is
known by the public and policymakers”.
Prof. James Hansen, 2008
AF
DR
What Lies Beneath 17
Y
NL
TO
UNDERSTATEMENT
AF
DR
What Lies Beneath 18
CLIMATE MODELS
Climate modelling is at the core of the work by In the 2017 Fourth National Climate Assessment, US
the IPCC, and in developing future emission and government agencies found that “positive feedbacks
warming scenarios, but it is often too conservative (self-reinforcing cycles) within the climate system
and underestimates future impacts. have the potential to accelerate human-induced
A 2007 report on climate change and national climate change and even shift the Earth’s climate
security by the US Center for Strategic and system, in part or in whole, into new states that are
International Studies and the Center for a New very different from those experienced in the recent
American Security recognised that: “Recent past”, and whilst some feedbacks and potential
observations indicate that projections from climate state shifts can be modelled and quantified, “others
models have been too conservative; the effects can be modeled or identified but not quantified and
of climate change are unfolding faster and more some are probably still unknown”. Hence:
dramatically than expected” and that “multiple “ While climate models incorporate important
lines of evidence” support the proposition that the climate processes that can be well quantified,
2007 IPCC reports’ “projections of both warming they do not include all of the processes that can
and attendant impacts are systematically biased contribute to feedbacks, compound extreme
low”. For instance: events, and abrupt and/or irreversible changes.
“ The models used to project future warming For this reason, future changes outside the
either omit or do not account for uncertainty range projected by climate models cannot be
in potentially important positive feedbacks ruled out. Moreover, the systematic tendency of
that could amplify warming (e.g., release of climate models to underestimate temperature
greenhouse gases from thawing permafrost, change during warm paleoclimates suggests that
reduced ocean and terrestrial CO2 removal from climate models are more likely to underestimate
the atmosphere), and there is some evidence than to overestimate the amount of long-term
that such feedbacks may already be occurring in future change.”50
response to the present warming trend. Hence, At the 2017 climate policy conference in Bonn,
climate models may underestimate the degree Phil Duffy, the Director of the Woods Hole
of warming from a given amount of greenhouse Institute, explained that “the best example of
gases emitted to the atmosphere by human reticence is permafrost… It’s absolutely essential
activities alone. Additionally, recent observations that this feedback loop not get going seriously, if it
of climate system responses to warming (e.g., does there is simply no way to control it.” He says
changes in global ice cover, sea-level rise, tropical the scientific failure occurs because “none of this
storm activity) suggest that IPCC models is in climate models and none of this is considered
underestimate the responsiveness of some in the climate policy discussion… climate
aspects of the climate system to a given amount models simply omit emissions from the warming
of warming.”48 permafrost, but we know that is the wrong answer
In 2015, researchers reported on the long-term because that tacitly assumes that these emissions
feedbacks that global climate models ignore, as are zero and we know that’s not right”.51
illustrated in Figure 3, where grey bars within
the middle blue ellipse signify processes that are
assumed to be (partly) inactive or non-existent in
global climate models, but in reality are not.49
48 Campbell et al. 2007, op cit.
49 Knutti, R, & Rugenstein MAA 2015, ‘Feedbacks, climate sensitivity and the limits of linear models’, Philosophical Transactions of the Royal Society A, vol. 373,
20150146.
50 USGCRP 2017, Climate Science Special Report: Fourth National Climate Assessment, Volume I, [Wuebbles, DJ, DW Fahey, KA Hibbard, DJ Dokken, BC Stewart
& TK Maycock (eds.)], US Global Change Research Program, Washington, DC, USA..
51 UPFSI 2017, ‘James Hansen: Scientific Reticence A Threat to Humanity and Nature’, media conference, Bonn, 19 November 2017, <https://www.
youtube.com/watch?v=S7z61UZoppM>
What Lies Beneath 19
There is a consistent pattern in the IPCC of “ The emphasis on consensus in IPCC reports
presenting detailed, quantified (numerical) has put the spotlight on expected outcomes,
modelling results, but then briefly noting more which then become anchored via numerical
severe possibilities — such as feedbacks that the estimates in the minds of policymakers… it
models do not account for — in a descriptive, is now equally important that policymakers
non-quantified form. Sea levels, polar ice sheets understand the more extreme possibilities that
and some carbon-cycle feedbacks are three consensus may exclude or downplay… given
examples. Because policymakers and the media are the anchoring that inevitably occurs around
often drawn to headline numbers, this approach numerical values, the basis for quantitative
results in less attention being given to the most uncertainty estimates provided must be
devastating, high-end, non-linear and difficult-to- broadened to give observational, paleoclimatic,
quantify outcomes. or theoretical evidence of poorly understood
Consensus around numerical results can result in phenomena comparable weight with evidence
an understatement of the risks. Oppenheimer et al. from numerical modeling… One possible
point to the problem: improvement would be for the IPCC to fully
include judgments from expert elicitations.”52
months years decades centuries millennia millions
timescale
clouds, lapse rate, water vapour, albedo
upper ocean
CH4 from gas hydrates
observation
vegetation
aerosols, dust vegetation mediated
volcanoes
entire ocean
land ice sheets growing and shrinking
carbon cycle
weathering
GCM’s volcanic provinces
paleo proxies plate tectonics
subdecadal variability:
feedbacks here do not necessarily indicate future behaviour
Figure 3: Timescales of climate processes and inclusions of feedbacks in climate models. The coloured ellipses each cover different methods used to estimate
climate sensitivity: observations (left), global climate models (GCMs) (centre) and paleoclimate proxies (right). Light grey bars indicate processes that act on
timescales that a GCM can resolve, but are usually assumed to be (partly) inactive or non-existent. Dashed lines indicate timescales where specific feedbacks are
weaker or only operate under certain circumstances. The arrow for clouds, lapse rate, water vapour and albedo indicates that those feedbacks operate on short
timescales but, because the surface warming takes centuries or more to equilibrate, these feedbacks continue to change and affect the overall response of the
systems up to millennia (Credit: Knutti & Rugenstein 2015).
52 Oppenheimer, M, O’Neill, B, Webster, M & Agrawala, S 2007, ‘The Limits of Consensus’, Science, vol. 317, pp. 1505-1506.
What Lies Beneath 20
Glaciologist Prof. Eric Rignot, says that “one of the SEMI-EMPIRICAL MODELS
problems of IPCC is the strong desire to rely on A semi-empirical model is a simpler, physically
physical models”. He explains: plausible model of reduced complexity that
“ For instance, in terms of sea-level rise projection, exploits statistical relationships. It combines
the IPCC tends to downplay the importance of current observations with some basic physical
semi-empirical models. In the case of Antarctica, relationships observed from past climates, and
it may be another ten years before fully-coupled theoretical considerations relating variables
ice sheet–ocean–sea ice–atmosphere models through fundamental principles, to project future
get the southern hemisphere atmospheric climate conditions. For example, semi-empirical
circulation, the Southern Ocean and the ice models “can provide a pragmatic alternative to
sheet right using physical models, with the estimate the sea-level response”.55 Observing
full physics, at a high spatial resolution. In the past rates of sea-level change from the climate
meantime, it is essential to move forward our record when the forcing (energy imbalance in the
scientific understanding and inform the public system) was similar to today, gives insights into
and policy makers based on observations, basic how quickly sea levels may rise in the next period.
physics, simpler models, well before the full- Thus a semi-empirical approach to projecting
fledged physical models eventually get there.”53 future sea-level rise may relate the global sea-
level rise to global mean surface temperature.
It is important to understand the distinction
This approach was used by Rahmstorf in 2007,
between full climate models and the semi-empirical
to project a 0.5–1.4 metres sea-level rise by 2100,
approach, because IPCC reports appear to privilege
compared to the IPCC’s 2007 report, based on
the former at the expense of the latter. Sea-level-rise
GCMs, which gave a figure of 0.18–0.59.56
projections are a good example of this.
Semi-empirical models rely on observations from
FULLY-COUPLED MODELS climate history (paleoclimatology) to establish
Fully-coupled global climate models or general relationships between variables. In privileging
circulation models (GCMs) are mathematical GCMs over semi-empirical models, the IPCC
representations of the Earth’s climate system, downplays insights from Earth’s climate history.
based on the laws of physics and chemistry. Run
on computers, they simulate the interactions of the
important drivers of climate, including atmosphere–
oceans–land surface–ice interactions, to solve the
full equations for mass and energy transfer and
radiant exchange. Models are tested in the first
instance by hindsight: how well, once loaded with
the observed climate conditions (parameters) at
a time in the past, do they reproduce what has
happened since that point. They are limited by the
capacity of modellers to understand the physical
processes involved, so as to be able to represent
them in quantitative terms. For example, ice sheet
dynamics are poorly reproduced, and therefore key
processes that control the response of ice flow to
a warming climate are not included in current ice
sheet models. GCMs are being improved over time,
and new higher-capacity computers allow models
of finer resolution to be developed.54
53 Rignot, E, pers. comm., 8 August 2017.
54 Rahmstorf, S 2007, ‘A semi -empirical approach to projecting future sea-level rise, Science vol. 315, pp. 368-370.
55 Ibid.
56 Ibid.
What Lies Beneath 21
TIPPING POINTS
A tipping point may be understood as the The scientific literature on tipping points is
passing of a critical threshold in an Earth climate relatively recent. Our knowledge is limited because
system component — such as major ocean and a system-level understanding of critical processes
atmospheric circulation patterns, the polar ice and feedbacks is still lacking in key Earth climate
sheets, and the terrestrial and ocean carbon stores components, such as the polar regions, and “no
— which produces a step change in the system. serious efforts have been made so far to identify
Progress toward a tipping point is often driven and qualify the interactions between various
by positive feedbacks, in which a change in a tipping points”.58
component leads to further changes that eventually As discussed above, climate models are not yet
“feed back” onto the original component to amplify good at dealing with tipping points. This is partly
the effect. A classic case in global warming is the due to the nature of tipping points, where a
ice–albedo feedback, where decreases in the area particular and complex confluence of factors
of polar sea ice change surface reflectivity, trapping abruptly change a climate system characteristic
more heat from the sun and producing further sea- and drive it to a different state. To model this,
ice loss. all the contributing factors and their forces have
In some cases, passing one threshold will trigger to be well identified, as well as their particular
further threshold events, for example, where interactions, plus the interactions between tipping
substantial greenhouse gas releases from polar points. Researchers say that “complex, nonlinear
permafrost carbon stores increase warming, systems typically shift between alternative states in
releasing even more permafrost carbon in a positive an abrupt, rather than a smooth manner, which is
feedback, but also pushing other systems, such as a challenge that climate models have not yet been
polar ice sheets, past their threshold point. able to adequately meet”.59
In a period of rapid warming, most major tipping The GCF says that despite scientific evidence
points once crossed are irreversible in human that risks associated with tipping points “increase
time frames, principally due to the longevity of disproportionately as temperature increases from
atmospheric CO2 (a thousand years).57 For this 1°C to 2°C, and become high above 3°C”,60
reason, it is crucial that we understand as much as political negotiations have consistently disregarded
possible about near-term tipping points. the high-end scenarios that could lead to abrupt or
irreversible climate change. In its Global Catastrophic
Large-scale human interventions in slow-moving
Risks 2017 report, the Foundation concludes that
earth system tipping points might allow a tipping
“the world is currently completely unprepared to
point to be reversed; for example, by a large-scale
envisage, and even less deal with, the consequences
atmospheric CO2 drawdown program, or solar
of catastrophic climate change”.61
radiation management.
The IPCC has published few projections regarding
tipping-point thresholds, nor emphasised the
importance of building robust risk-management
assessments of them in the absence of adequate
quantitative data.
57 Solomon, S, Plattner, GK, Knutti, R & Friedlingstein, P 2008, ’Irreversible climate change due to carbon dioxide emissions’, Proceedings of the National
Academy of Sciences, vol. 106, no. 6, pp. 1704–1709.
58 Schellnhuber, HJ 2009, ‘Tipping elements in the Earth system’, Proceedings of the National Academy of Sciences, vol. 106, no. 49, pp. 20561–20563.
59 Duarte, C, Lenton, T, Wadhams, P & Wassmann, P 2012, ‘Abrupt climate change in the Arctic’, Nature Climate Change, vol. 2, pp. 60–62.
60 GFC 2017, op. cit.
61 ibid.
What Lies Beneath 22
CLIMATE SENSITIVITY
The question of climate sensitivity is a vexed The rate of change in energy forcing is now
one. Climate sensitivity is the amount by which so great that these “long-term” feedbacks have
the global average temperature will rise due to a already begun to operate within short time frames.
doubling of the atmospheric greenhouse gas level, The IPCC is not forthcoming on this issue. Instead
at equilibrium. (Equilibrium refers to the state of it sidesteps with statements (from 2007) such as this:
a system when all the perturbations have been “Models used to date do not include uncertainties
resolved and the system is in balance.) in climate–carbon cycle feedback... because a basis
IPCC reports have focused on what is generally in published literature is lacking... Climate–carbon
called Equilibrium Climate Sensitivity (ECS). The cycle coupling is expected to add CO2 to the
2007 IPCC report gives a best estimate of climate atmosphere as the climate system warms, but the
sensitivity of 3°C and says it “is likely to be in the magnitude of this feedback is uncertain.” This is
range 2°C to 4.5°C”. The 2014 report says that the type of indefinite language that politicians and
“no best estimate for equilibrium climate sensitivity the media are likely to gloss over, in favour of a
can now be given because of a lack of agreement headline number.
on values across assessed lines of evidence and It should be noted that carbon budgets — the
studies” and only gives a range of 1.5°C to 4.5°C. amount of carbon that could be emitted before a
This was a backward step.62 temperature target is exceeded — are generally
What the IPCC reports fail to make clear is that the based on a climate sensitivity mid-range value
ECS measure omits key “long-term” feedbacks that around 3°C. Yet this figure may be too low. Fasullo
a rise in the planet’s temperature can trigger. These and Trenberth found that the climate models that
include the permafrost feedback and other changes most accurately capture observed relative humidity
in the terrestrial carbon cycle, a decrease in the in the tropics and subtropics and associated clouds
ocean’s carbon-sink efficiency, and the melting of were among those with a higher sensitivity of
polar ice sheets creating a cold ocean-surface layer around 4°C.64 Sherwood et al. also found a
underneath that accelerates the melting of ice sensitivity figure of greater than 3°C.65 Zhai et al.
shelves and hastens the rate of ice-mass loss. found that climate models that are consistent with
the observed seasonal variation of low-altitude
Climate sensitivity which includes these feedbacks
marine clouds have an average sensitivity of
— known as Earth System Sensitivity (ESS) —
3.9°C. 66 Recently it has been demonstrated the
does not appear to be acknowledged in the 2014
models that best capture current conditions have
IPCC reports at all. Yet, there is a wide range of
a mean value of 3.7°C compared to 3.1°C by the
literature which suggest an ESS of 4–6°C.63
raw model projections.67
It is conventionally considered that these “long-
The work on existential climate risks by Xu and
term” feedbacks –– such as changes in the polar
Ramanathan, cited above, is also important in
carbon stores and the polar ice sheets –– operate
assessing what is an appropriate climate sensitivity
on millennial timescales. Yet the rate at which
for risk-management purposes, for three reasons.
human activity is changing the Earth’s energy
balance is without precedent in the last 66 million
years, and about ten times faster than during
the Paleocene–Eocene Thermal Maximum 55
million years ago, a period with one of the largest
extinction events on record.
62 References to the IPCC are drawn from the relevant Working Group, Synthesis and the Summary for Policymakers reports.
63 The Geological Society 2013, An addendum to the Statement on Climate Change: Evidence from the geological record, The Geological Society, London, December
2013; Hansen, J, Sato, M, Russell, G & Kharecha, P 2013, ’Climate sensitivity, sea level and atmospheric carbon dioxide’, Philosophical Transactions of the
Royal Society A, vol. 371, no. 2001, 20120294.
64 Fasullo, J & Trenberth, K 2012, ’A less cloudy future: the role of subtropical subsidence in climate sensitivity’, Science, vol. 338, no. 6108, pp. 792-794.
65 Sherwood, S, Bony, S & Dufresne, JL 2014, ’Spread in model climate sensitivity traced to atmospheric convective mixing’, Nature, vol. 505, pp. 37-42.
66 Zhai, C, Jiang, J & Su, H 2015, ’Long-term cloud change imprinted in seasonal cloud variation: More evidence of high climate sensitivity’, Geophysical
Research Letters, vol. 42, no. 20, pp. 8729-8737.
67 Brown, P & Caldeira, K 2017, ‘Greater future global warming inferred from Earth’s recent energy budget’, Nature, vol. 552, pp. 45-50.
What Lies Beneath 23
They say that: “We are now at a tipping point that
1. Taking into account the biogeochemical
feedbacks (such as less efficient land/ocean
threatens to flip the world into a full blown
sinks, including permafrost loss) effectively climate emergency.”
increases carbon emissions to 2100 by about Tony de Brum, Mary Robinson and Kelly Rigg, 2013
20% and can enhance warming by up to
0.5°C, compared to a baseline scenario.
2. Warming has been projected to increase methane
emissions from wetlands by 0–100% compared
with present-day wetland methane emissions.
A 50% increase in wetland methane emissions
by 2100 in response to high-end warming of
4.1–5°C could add at least another 0.5°C.
3. It is important to use high-end climate sensitivity
because some studies have suggested that climate
models have underestimated three major positive
climate feedbacks: positive ice albedo feedback
from the retreat of Arctic sea ice; positive cloud
albedo feedback from retreating storm track
clouds in mid-latitudes; and positive albedo
feedback by the mixed-phase (water and ice)
clouds. When these are taken into account, the
ECS is more than 40% higher than the IPCC
mid-figure, at 4.5-4.7°C, before adding up to
another 1°C of warming as described in 1. and
2. above.68
In research published in 2016, Friedrich et al.
show that climate models may be underestimating
climate sensitivity because it is not uniform across
different circumstances, but in fact higher in
warmer, interglacial periods (such as the present)
and lower in colder, glacial periods.69 Based on a
study of glacial cycles and temperatures over the
last 800,000 years, the authors conclude that in
warmer periods climate sensitivity averages around
4.88°C. The higher figure would mean warming
for 450 parts per million (ppm) of atmospheric
CO2 (a figure on current trends we will reach
within 25 years) would be around 3°C, rather than
the 2°C bandied around in policy making circles.
Professor Michael Mann, of Penn State University,
says the paper appears “sound and the conclusions
quite defensible”.70
68 Xu, Y & Ramanathan, V 2017, ‘Well below 2 °C: Mitigation strategies for avoiding dangerous to catastrophic climate changes’, Proceedings of the National
Academy of Sciences, vol. 114, pp. 10315-10323.
69 Friedrich, T, Timmermann, A, Timm, OE & Ganopolski, A 2016, ‘Nonlinear climate sensitivity and its implications for future greenhouse warming’,
Science Advances, vol. 2, no. 11, e1501923.
70 Johnston, I 2016, ‘Climate change may be escalating so fast it could be “game over”, scientists warn’, Independent, 9 November 2016.
What Lies Beneath 24
CARBON BUDGETS
A carbon budget is an estimate of the total future models for RCP6.0.72 (RCPs are representative
human-caused greenhouse gas emissions, in tons concentration pathways of greenhouse gas emission
of carbon, CO2 or CO2 equivalent, that would be trajectories. RCP2.6 is the lowest and RCP8.5 is the
consistent with limiting warming to a specified figure, highest.) This is consistent with findings five years
such as 1.5°C or 2°C, with a given risk of exceeding earlier that climate model projections which show a
the target, such as a 50%, 33% or 10% chance. greater rise in global temperature are likely to prove
The discussion of carbon budgets is frequently more accurate than those showing a lesser rise.73
opaque. Often, it is difficult to ascertain whether As well, the IPCC uses a definition of global
the assumptions are realistic, for example whether a mean surface temperature that underestimates the
budget includes non-CO2 forcings such as methane amount of warming over the pre-industrial level.
and nitrous oxide. Too often, the risk of failure is not When estimates for the effect of calculating (1)
clearly spelt out, especially the fat-tail risks. Contrary warming for total global coverage rather than for
to the tone of the IPCC reports, the evidence shows the coverage for which observations are available,
we have no carbon budget for 2°C for a sensible (2) warming using surface air temperature
risk-management, low-probability (of a 10%, or measurements (SATs) over the entire globe
one-in-ten) chance of exceeding that target. The instead of the observational blend of sea surface
IPCC reports fail to say there is no carbon budget temperatures (SSTs) and SATs, and (3) warming
if 2°C is considered a cap (an upper boundary not from a pre-industrial, instead of a late-nineteenth
to be exceeded) as per the Copenhagen Accord, rather century baseline, are taken into account, the
than a target (an aspiration which can be significantly underestimation is around 0.3°C. This results in a
exceeded). The IPCC reports fail to say that once significant overestimation of allowable emissions.74
projected emissions from future food production For example, for stabilization at 2°C, allowable
and deforestation are taken into account, there is emissions decrease by as much as 40% when
no carbon budget for fossil-fuel emissions for a 2°C earlier than nineteenth-century climates are
target.71 considered as a baseline.75
Carbon budgets are routinely proposed that have There are also problems with carbon budgets
a substantial and unacceptable risk of exceeding which incorporate “overshoot” scenarios, in which
specified targets and hence entail large and warming exceeds the target before being cooled by
unmanageable risks of failure. carbon drawdown. Pam Pearson, Director of the
Research published in December 2017 compared International Cryosphere Climate Initiative, says
“raw” climate models (used by the IPCC) with that most cryosphere thresholds are determined
models that are “observationally informed” and best by peak temperature, and the length of time
capture current conditions. The latter produce 15% spent at that peak, warning that “later, decreasing
more warming by 2100 than the IPCC suggests, temperatures after the peak are largely irrelevant,
thus reducing the carbon budget by around 15% for especially with higher temperatures and longer
the 2°C target. Hence, as one example, the actual duration peaks”. Thus “overshoot scenarios”,
warming for the RCP4.5 emissions path is in reality which are now becoming the norm in policymaking
likely to be higher, similar to that projected by raw circles, hold much greater risks.76
71 Raupach, M 2013, pers. comm, 20 October 2013, based on Raupach, M, Harman, IN & Canadell, GJ 2011, Global climate goals for temperature,
concentrations, emissions and cumulative emissions, The Centre For Australian Weather and Climate Research, Melbourne 2011, discussed at http://www.
climatecodered.org/2014/05/thereal-budgetary-emergency-burnable.html; Arora, VK, Scinocca, JF, Boer, GJ, Christian, RJ, Denman, KL, Flato, GM,
Kharin, VV, Lee, WG & Merryfield, WJ 2015, ‘Carbon emission limits required to satisfy future representative concentration pathways of greenhouse
gases’, Geophysical Research Letters, vol. 38, L05805; Meinshausen, M 2008, ‘The EU, the IPCC and the science of climate change: The 2°C target’, IES
Autumn lecture series, 8 October 2008, Brussels; Anderson, K & and Bows, A 2008, ‘Reframing the climate change challenge in light of post-2000
emission trends, Philosophical Transactions of the Royal Society A, vol. 366, pp. 3863-3882.
72 Brown, P & Caldeira, K 2017, ‘Greater future global warming inferred from Earth’s recent energy budget’, Nature, vol. 552, pp. 45-50.
73 Fasullo, JT & Trenberth, KE 2012, ‘A Less Cloudy Future: The Role of Subtropical Subsidence in Climate Sensitivity’, Science, vol. 338, pp. 792-794.
74 Schurer, AP, Cowtan, K, Hawkins, E, Mann, ME, Scott, V & Tett, SFB 2018, ‘Interpretations of the Paris climate target’, Nature Geoscience, vol 11, pp.
220.
75 Schurer, A, Mann, ME, Hawkins, E, Tett, SFB & Hegerl, GC 2017, ‘Importance of the pre-industrial baseline for likelihood of exceeding Paris goals’,
Nature Climate Change, vol. 7, pp. 563-568.
76 UPFSI 2017, op cit.
What Lies Beneath 25
PERMAFROST AND
THE CARBON CYCLE
The failure to adequately consider long-term a net carbon source. The tropics are now a net
feedbacks in IPCC estimates of climate sensitivity carbon source, with losses owing to deforestation
in climate models, and hence in projections of and reductions in carbon density within standing
future warming, lies at the heart of the problem forests being double that of gains resulting from
with the IPCC reporting process. Over century forest growth.82 Other work has projected a long-
time-scales, amplifying feedbacks may ultimately term, self-reinforcing carbon feedback from mid-
contribute 28–68% of total warming, yet they latitude forests to the climate system as the world
comprise only 1–7% of current warming.77 The warms.83
land sink (storage capacity) for CO2 appears much There has been an observed decline in the
smaller than is currently factored into some climate Amazon carbon sink. Negative synergies between
models.78 Thus, future patterns of warming may deforestation, climate change, and widespread use
be distinctly different from past patterns, making of fire indicate a tipping point for the Amazon
it difficult to predict future warming by relying on system to flip to non-forest ecosystems in eastern,
past observations. southern and central Amazonia at 20–25%
deforestation. Researchers say the severe droughts
SOIL CARBON
of 2005, 2010 and 2015-16 could well represent
A 2016 study concluded that a soil carbon- the first flickers of this ecological tipping point, and
cycle feedback “has not been incorporated into say the whole system is oscillating.84
computer models used to project future climate
change, raising the possibility that such models are PERMAFROST
underestimating the amount of warming that is The world’s permafrost holds 1.5 trillion tons of
likely to occur”.79 The projected loss of soil carbon frozen carbon, more than twice the amount of
resulting from climate change is a potentially carbon in the atmosphere. On land, it covers an
large but highly uncertain feedback to warming, area of 15 million square kilometres. The Arctic is
however there is likely to be strong carbon-climate warming faster than anywhere else on Earth, and
feedbacks from colder northern soils.80 some permafrost degradation is already occurring.
Large-scale tundra wildfires in 2012 added to the
FORESTS
concern, as have localised methane outbursts.
At the moment about one-third of human-caused
The 2007 IPCC assessment on permafrost did
CO2 emissions are absorbed by trees and other
not venture beyond saying: “Changes in snow,
plants. But rapid climate warming and unusual
ice and frozen ground have with high confidence
rainfall patterns are jeopardising many of the
increased the number and size of glacial lakes,
world’s trees, due to more frequent drought,
increased ground instability in mountain and other
pest outbreaks and fires. This is starting to have
permafrost regions and led to changes in some
profound effects on the Earth’s carbon cycle.
Arctic and Antarctic ecosystems”. It reported with
In 2009, researchers found that 2°C of warming “high confidence” that “methane emissions from
could cut in half the carbon sink of tropical tundra… and permafrost have accelerated in the past
rainforests.81 Some tropical forests — in the Congo, two decades, and are likely to accelerate further”. It
and in Southeast Asia — have already shifted to offered no projections regarding permafrost melt.
77 Proistosescu, C & Huybers, P 2017, ‘Slow climate mode reconciles historical and model-based estimates of climate sensitivity’, Science Advances, vol. 3,
e1602821.
78 Bradford, A 2017, ‘A leaky sink’, Nature Climate Change, vol. 7, pp. 475-476
79 Crowther T. et al. 2016, ‘Quantifying global soil carbon losses in response to warming’, Nature, vol. 540, pp. 104-108.
80 Koven, C, Hugelius, G, Lawrence, DM & Wieder, WR 2017, ‘Higher climatological temperature sensitivity of soil carbon in cold than warm climates’,
Nature Climate Change, vol. 7, pp. 817-822.
81 Murray, J 2009, ‘Research warns two degree rise will halve rainforest “carbon sink”’, Business Green, 3 March 2009, <http://www.businessgreen.com/
business-green/news/2237656/research-warns-two-degree>.
82 Baccini, A, Walker, W, Carvalho, L, Farina, M, Sulla-Menashe, D & Houghton, RA 2017, ‘Tropical forests are a net carbon source based on
aboveground measurements of gain and loss’, Science, vol. 358, pp. 230-234.
83 Melillo, JM, Frey, SD, DeAngelis, KM, Werner, WJ, Bernard, MJ, Bowles, FP, Pold, G, Knorr, MA & Grandy, AS 2017, ‘Long-term pattern and
magnitude of soil carbon feedback to the climate system in a warming world’, Science, vol. 358, pp. 101-105.
84 Lovejoy, T & Nobre, C 2018, ‘Amazon Tipping Point’, Science Advances, vol. 4, eaat2340.
What Lies Beneath 26
Yet, in 2005, Lawrence and Slater had shown that the ocean floor on the shallow East Siberian
a doubling of CO2 levels by 2100 — a path to 3°C Arctic Shelf (ESAS). (Methane hydrates are
of warming — would reduce the land permafrost cage-like lattices of ice within which methane
area by more than half and melt much of the top molecules are trapped.)
three metres.85 (In 2017, permafrost area loss was These stores are protected from the warmer ocean
estimated to be 4 million square kilometres for each temperatures above by a layer of frozen sub-sea
1°C of warming.) permafrost. The concern is that warmer water could
The 2014 Summary for Policymakers (SPM) said: “It is create taliks (areas of unfrozen permafrost) through
virtually certain that near-surface permafrost extent which large-scale methane emissions from the
at high northern latitudes will be reduced as global hydrates could escape into the water column above,
mean surface temperature increases, with the area and into the atmosphere. This possibility was raised
of permafrost near the surface (upper 3.5 meters) in 2013 by Whiteman, Hope and Wadhams.90
projected to decrease by 37% (RCP2.6) to 81% Prof. Peter Wadhams explained that “the loss of
(RCP8.5) for the multi-model average (medium sea ice leads to seabed warming, which leads to
confidence).” That was it. offshore permafrost melt, which leads to methane
The effect of the permafrost carbon feedback has release, which leads to enhanced warming, which
not been included in the IPCC scenarios, including leads to even more rapid uncovering of seabed”,
the 2014 report.86 This is despite clear evidence and this is not “a low probability event”.91
that “the permafrost carbon feedback will change More than a few experts derided these claims. The
the Arctic from a carbon sink to a source after the model estimates reported by the IPCC are that the
mid-2020s and is strong enough to cancel 42–88% degradation of ESAS permafrost cannot exceed
of the total global land sink”. In 2012, researchers several metres this century, and the formation of
found that, for the 2100 median forecasts, there taliks that would allow the release of large amounts
would be 0.23–0.27°C of extra warming due to of methane will take hundreds or thousands of
permafrost feedbacks. Some scientists consider that years. Thus the IPCC considers the potential
1.5°C appears to be something of a “tipping point” contribution of the ESAS into the emissions of
for extensive permafrost thaw.87 methane as insignificant.92
A 2014 study estimated that up to 205 billion But researchers say that model is no longer correct.
tonnes equivalent of CO2 could be released due In August 2017, they announced that:
to melting permafrost. This would cause up
“ In some areas of the East Siberian Arctic Shelf
to 0.5°C extra warming for the high emissions
the roof of the subsea permafrost had already
scenario, and up to 0.15°C of extra warming for
reached the depth of hydrates’ stability the
a 2°C scenario. The authors say that: “Climate
destruction of which may cause massive releases
projections in the IPCC Fifth Assessment Report, and
of bubble methane… The results of our study
any emissions targets based on those projections, do
ensure fundamentally new insights of the
not adequately account for emissions from thawing
mechanism of processes responsible for the state
permafrost and the effects of the permafrost
of subsea permafrost in the East Siberian Arctic
carbon feedback on global climate.”88
Shelf which, according to various estimates,
But, even if human greenhouse gas emissions are concentrates up to 80% and more of entire
stabilised, permafrost carbon loss may continue for subsea permafrost in the Northern Hemisphere,
many years and simulations suggest that 225 to 345 under which there are huge hydrocarbon reserves
billion tonnes of CO2 may eventually be released to in the forms of hydrates, oil and free gas.”93
the atmosphere for the stabilization target of 2°C.89
A deceptively optimistic picture is painted when
Recently attention has turned to the question of
the potential impacts from the degradation of
the stability of large methane hydrate stores below
permafrost and methane hydrates are underplayed.
85 Lawrence, DM & Slater, AG 2005, ‘A projection of severe near‐surface permafrost degradation during the 21st century’, Geophysical Research Letters, vol.
32, L22401.
86 UNEP 2012, Policy Implications of Warming Permafrost, United Nations Environment Program, Nairobi.
87 MacDougall, A, Avis, C & Weaver, AJ 2012, ’Significant contribution to climate warming from the permafrost carbon feedback’, Nature Geoscience, vol. 5,
pp. 719–721; Schaefer, K, Zhang, T, Bruhwiler & Barrett, A 2011, ‘Amount and timing of permafrost carbon release in response to climate warming’,
Tellus B, vol. 63, no. 2, pp. 165-180; Vaks, A, Gutareva, OS, Breitenbach, SF, Avirmed, E, Mason, AJ, Thomas, AL, Osinzev, AV & Henderson, GM
2013, ‘Speleothems reveal 500,000-year history of Siberian permafrost’, Science, vol. 340, no. 6129, pp. 183-186.
88 Schaefer, K, Lanuit, H, Romanovsky, V, Schuur, E & Witt, R 2014, ‘The impact of the permafrost carbon feedback on global climate’, Environmental
Research Letters, vol. 9, no. 8, 085003.
89 Burke, EJ, Chadburn, SE, Huntingford, C & Jones, CD 2018, ‘CO2 loss by permafrost thawing implies additional emissions reductions to limit warming
to 1.5 or 2°C’, Environmental Research Letters, vol. 13, 024024.
90 Whiteman, G, Hope, C & Wadhams, P 2013, ‘Climate science: Vast costs of Arctic change”, Nature, vol. 499, pp. 401–403.
91 Ahmed, N 2013, ‘Ice-free Arctic in two years heralds methane catastrophe – scientist’, The Guardian, 25 July 2103 .
92 Tomsk Polytechnic University 2017, Russian scientists deny climate model of IPCC’, Eureka Alert, 15 August 2017, <https://www.eurekalert.org/
pub_releases/2017-08/tpu-rsd081517.php>.
93 Ibid.
What Lies Beneath 27
ARCTIC SEA ICE
In 2007, the IPCC reported: “Satellite data since Yet, in an astonishing understatement, the 2014
1978 show that annual average Arctic sea-ice IPCC report said: “Year-round reductions in Arctic
extent has shrunk by 2.7% per decade” and “late sea ice are projected for all RCP scenarios.” It said
summer sea ice is projected to disappear almost a nearly ice-free Arctic Ocean in the summer was
completely towards the end of the twenty-first likely for the highest emissions scenario only.
century”. In reality, summer ice is thinning faster than every
That same year, the summer retreat of Arctic sea climate projection, tipping points have been crossed
ice wildly out-distanced all 18 IPCC computer for sea-ice-free summer conditions, and today
models. One scientist exclaimed that is was scientists say an ice-free summer Arctic could be
melting “one hundred years ahead of schedule”. just years away, not many decades.
Many models, including those on which the 2007 Model limitations “are hindering our ability to
IPCC report had relied, did not fully capture the predict the future state of Arctic sea ice” and the
dynamics of sea-ice loss. majority of general climate models “have not been
Prof. Michael E. Mann says sea-ice modellers able to adequately reproduce observed multi-
had “speculated that the 2007 minimum was an decadal sea-ice variability and trends in the pan-
aberration… a matter of random variability, noise Arctic region”, so their trend in September Arctic
in the system, that sea ice would recover.… that no sea-ice extent “is approximately 30 years behind
longer looks tenable”.94 the observed trend”.96
Yet, two years earlier, Prof. Tore Furevik of the The loss of sea ice reduces the planet’s reflectivity
Geophysical Institute in Bergen had already and adds to warming, but this positive feedback is
demonstrated that actual Arctic sea-ice retreat had not fully incorporated into models in circumstances
been greater than estimates in any of the Arctic where the rate of sea-ice loss is more rapid than
models reported by the IPCC. By 2007, a wider expected in the models, as is occurring now. To
range of scientists had presented evidence that the keep global temperature increase below 2°C, global
Arctic may be free of all summer sea-ice as early as CO2 emissions would need to reach zero 5–15
2030.95 Of this, the 2007 IPCC report said nothing. years earlier and the carbon budget would need
There was a similar, mind-numbing drop in Arctic to be reduced by 20–51% to offset this additional
sea ice in 2012 to levels unseen in millennia, with the source of warming.97
summer minimum sea-ice volume just one-third of Because climate models are missing key real-
that just 30 years earlier, increasing the margin by world interactions and generally have been poor
which IPCC projections had been too conservative. at dealing with the rate of Arctic sea-ice retreat,
expert elicitations play a key role in considering
whether the Arctic has passed a very significant and
dangerous tipping point.98 But the IPCC has not
done this.
94 Scherer 2012a, op. cit.
95 Serreze, MC, Holland, MM & Stroeve, J 2007, ‘Perspectives on the Arctic’s shrinking sea ice cover’, Science, vol. 315, no. 5818, pp. 1533-1536; Stroeve, J,
Holland, MM, Meier, W, Scambos, T & Serreze, M 2007, ‘Arctic sea ice decline: Faster than forecast?’, Geophysical Research Letters, vol. 34, no. 9, L09501.
96 Maslowski, W, Kinney, JC, Higgins, M & Roberts, A 2012, ‘The future of Arctic sea ice’, The Annual Review of Earth and Planetary Sciences, vol. 20, pp. 625-
654.
97 Gonzalez-Eguino, M, Neumann, MB, Arto, I, Capellán‐Perez, I & Faria, SH 2017, ‘Mitigation implications of an ice-free summer in the Arctic Ocean’,
Earth’s Future, vol. 5, pp. 59-66.
98 Livina, VN & Lenton, TM 2013, ‘A recent tipping point in the Arctic sea-ice cover: abrupt and persistent increase in the seasonal cycle since 2007’, The
Cryosphere, vol. 7, pp. 275-286; Maslowski, Kinney et al 2012., op. cit.
What Lies Beneath 28
POLAR ICE-MASS
LOSS
In 1995, the IPCC projected “little change in Ice Sheet would be a period “over a millennium
the extent of the Greenland and Antarctic ice or more”, with a threshold between 1°C and 4°C
sheets… over the next 50-100 years”. The 2001 of warming. In fact, the annual rate of loss had
IPCC report suggested that neither the Greenland doubled in the period 2003 to 2010 compared with
nor the Antarctic ice sheets would lose significant the rate throughout the 20th century.101
mass by 2100. By this time, many leading cryosphere scientists
The 2007 IPCC report said there were were saying informally that Greenland had passed
“uncertainties… in the full effects of changes in ice its tipping point, “is already lost”, and similar
sheet flow”, and a suggestion that “partial loss of ice sentiments. And a year before, a significant
sheets on polar land could imply metres of sea-level research paper had estimated the tipping point for
rise… Such changes are projected to occur over Greenland Ice Sheet as 1.6°C (with an uncertainty
millennial time scales”. The reality is very different. range of 0.8 to 3.2°C). And there was clear satellite
evidence of accelerating ice-mass loss.102
GREENLAND ICE SHEET
The loss of ice mass from Greenland is
In 2007, the IPCC reported: “Contraction of the accelerating, which is drawing increasing levels of
Greenland Ice Sheet is projected to continue to concerns from scientists. “What keeps cryosphere
contribute to sea-level rise after 2100. Current scientists up at night are irreversible thresholds,
models suggest virtually complete elimination particularly West Antarctica and Greenland,”
of the Greenland Ice Sheet and a resulting says Pam Pearson, Director of the International
contribution to sea-level rise of about seven metres Cryosphere Climate Initiative.103
if global average warming were sustained for
Current-generation climate models are not yet all
millennia in excess of 1.9 to 4.6°C relative to pre-
that helpful for predicting Greenland ice-mass loss.
industrial values.”
They have a poor understanding of the processes
This was despite two 2006 studies, which found involved, and the acceleration, retreat and thinning
the Greenland ice cap “may be melting three times of outlet glaciers are poorly or not represented.104
faster than indicated by previous measurements”,
In the case of Greenland, the adverse
warnings that “we are close to being committed to
consequences for policymaking of the IPCC’s
a collapse of the Greenland Ice Sheet” and reports
method of privileging global climate model
that rising Arctic regional temperatures are already
results over observations, historical data and
at “the threshold beyond which glaciologists think
expert elicitations can be clearly seen. It is hard
the [Greenland] ice sheet may be doomed”.99
not to imagine the rate of Greenland Ice Sheet
The 2007 assessment “did not take into account deglaciation continuing to accelerate as the climate
the potential melting of Greenland, which I continues to warm, reflectivity declines, and late
think was a mistake”, said Robert Watson, Chief summer ocean conditions become sea-ice free.
Scientific Advisor for Britain’s Department for
In 2012, then NASA climate science chief James
Environmental Affairs and chairman of the IPCC’s
Hansen told Bloomberg that: “Our greatest
2001 assessment.100
concern is that loss of Arctic sea ice creates a
By 2014, the IPCC was reporting that “over the grave threat of passing two other tipping points
period 1992 to 2011, the Greenland and Antarctic – the potential instability of the Greenland Ice
ice sheets have been losing mass, likely at a larger Sheet and methane hydrates… These latter two
rate over 2002 to 2011”. The loss of the Greenland
99 Rignot, E & Kanagaratnam, P 2006, ‘Changes in the velocity structure of the Greenland ice sheet’, Science, vol. 311, no. 5763, pp. 986-90; Chen, JL,
Wilson, CR & Tapley, BD 2006, ‘Satellite gravity measurements confirm accelerated melting of Greenland ice’, Science, vol. 313, pp. 1958–60; Young, K
2006, “Greenland ice cap may be melting at triple speed”, New Scientist, 10 August, 2006.
100 AFP 2008, ‘Climate change gathers steam, say scientists’, Space Daily, 30 November 2008, <http://www.spacedaily.com/2006/081130055637.szeh21pj.
html>.
101 Mooney, C, 2015, ‘Greenland has lost a staggering amount of ice — and it’s only getting worse’, Washington Post, 16 December 2015.
102 Robinson, A, Calov, R & Ganopolski, A 2012, ‘Multistability and critical thresholds of the Greenland ice sheet’, Nature Climate Change, vol. 2, pp.
429–432.
103 UPFSI 2017, op cit.
104 Maslowski, Kinney et al. 2012, op cit.
What Lies Beneath 29
tipping points would have consequences that are This was a world away from the IPCC report of
practically irreversible on time scales of relevance the same year.
to humanity.”105 In 2016, another significant study concluded that:
On this very grave threat, the IPCC is mute. “Antarctica has the potential to contribute more
than a metre of sea-level rise by 2100 and more
ANTARCTIC ICE SHEET than 15 metres by 2500.”108 Compare this to the
The 2007 IPCC assessment proffered: “Current IPCC report, just a year earlier, that Antarctica’s
global model studies project that the Antarctic ice contribution to rising sea levels would “not exceed
sheet will remain too cold for widespread surface several tenths of a meter… during the 21st century”.
melting and gain mass due to increased snowfall. As well, partial deglaciation of the East Antarctic
However, net loss of ice mass could occur if ice sheet is likely for the current level of
dynamical ice discharge dominates the ice sheet atmospheric CO2, contributing ten metres or more
mass balance.” Reality and new research would soon of sea-level rise in the longer run, and five metres
undermine this one-sided reliance by the IPCC on in the first 200 years.109
models with poor cryosphere performance.
The increasing rate of change in Antarctica was
By the 2014 IPCC assessment, the story brought to light with the publication, in June 2018,
was: “Based on current understanding (from of the most-comprehensive-yet analysis of changes
observations, physical understanding and to the ice sheet. The new data showed that ocean-
modelling), only the collapse of marine-based driven melting has caused rates of ice loss from
sectors of the Antarctic Ice Sheet, if initiated, could West Antarctica to triple from 53 ± 29 billion to 159
cause global mean sea level to rise substantially ± 26 billion tonnes per year from 1992 to 2017.110
above the likely range during the 21st century. Forty percent of the total ice mass loss over that
There is medium confidence that this additional period has occurred in the last five years, suggesting
contribution would not exceed several tenths of a recent and significant acceleration in the loss rate.
a metre of sea-level rise during the 21st century.”
Over the same period, ice-shelf collapse had
And: “Abrupt and irreversible ice loss from the
increased the rate of ice loss from the Antarctic
Antarctic ice sheet is possible, but current evidence
Peninsula almost five-fold from 7 ± 13 billion to 33
and understanding is insufficient to make a
± 16 billion tonnes per year. Two West Antarctic
quantitative assessment.” This was another blunder.
glaciers – Pine Island and Thwaites — are of
Observations of accelerating ice mass loss in West particular concern, with the latter “increasingly
Antarctica were well established by this time.106 being viewed as posing a potential planetary
It is likely that the Amundsen Sea sector of the West emergency because of its enormous size and its role
Antarctic Ice Sheet has already been destabilized. as a gateway that could allow the ocean to someday
Ice retreat is unstoppable for the current conditions, access the entirety of West Antarctica, turning the
and no acceleration in climate change is necessary to marine-based ice sheet into a new sea”.111
trigger the collapse of the rest of the West Antarctic This is the scenario Prof. James Hansen warned
Ice Sheet, with loss of a significant fraction on a about a decade ago in a paper on sea-level rise
decadal-to-century time scale. One of the most and scientific reticence: “Let us say that the ice
significant research findings in 2014 was that the sheet contribution is one centimetre for the decade
tipping point has already passed for one of these 2005-2015 and that it doubles each decade until
“long-term” events. Scientists found that “the retreat the West Antarctic Ice Sheet is largely depleted.
of ice in the Amundsen Sea sector of West Antarctica That time constant yields sea-level rise of the order
was unstoppable, with major consequences – it will of five metres this century. Of course I can not
mean that sea levels will rise one metre worldwide… prove that my choice of a ten-year doubling time
Its disappearance will likely trigger the collapse of for non-linear response is accurate, but I would bet
the rest of the West Antarctic ice sheet, which comes $1000 to a donut that it is a far better estimate than
with a sea-level rise of between 3–5 metres. Such an a linear response for the ice sheet component of
event will displace millions of people worldwide.”107 sea-level rise [of around 0.5 metre].”112
105 Bloomberg, 2012, ‘Arctic sea ice heads for record low’, Bloomberg, 17 August 2012, <http://www.bloomberg.com/news/2012-08-17/arctic-sea-ice-
heads-for-record-low-as-melt-exceeds-forecasts.html>.
106 Velicogna, I 2009, ‘Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE’, Geophysical Research Letters, vol. 36,
L19503.
107 Rignot, E, Mouginot, J, Morlighem, M, Seroussi, H & Scheuchl, B 2014, ‘Widespread, rapid grounding line retreat of Pine Island, Thwaites, Smith, and
Kohler glaciers, West Antarctica, from 1992 to 2011’, Geophysical Research Letters, vol. 41, pp. 3502–3509.
108 DeConto, R & Pollard, D 2016, ‘Contribution of Antarctica to past and future sea-level rise’, Nature, vol. 531, pp. 591–597.
109 Pollard, D, DeConto, R & Alley, R 2015, ‘Potential Antarctic Ice Sheet retreat driven by hydrofracturing and ice cliff failure’, Earth Planetary Science Letters,
vol. 412, pp. 112– 121.
110 The IMBIE Team 2018, “Mass balance of the Antarctic Ice Sheet from 1992 to 2017”, Nature, vol. 558, pp. 219–222.
111 Mooney, C 2018, “Antarctic ice loss has tripled in a decade. If that continues, we are in serious trouble”, Washington Post, 13 June 2018.
112 Hansen, J 2007, op. cit.
What Lies Beneath 30
SEA LEVEL RISE
The fate of the world’s coastlines has become a Within a year, a report from the US Geological
classic example of how the IPCC, when confronted Survey warned that sea-level rise will “substantially
with conflicting science, tends to go for the “least exceed” official UN projections and could top
drama” position. 1.5 metres by the end of the century.115 And by
In the 2001 assessment report, the IPCC projected 2009, various studies offered drastically higher
a sea-level rise of 2 millimetres per year. By 2007, projections than the IPCC. Australian Government
the researchers found that the range of the 2001 reports noted: “Recent research, presented at the
predictions were lower than the actual rise. Satellite Copenhagen Climate Congress in March 2009,
data showed that levels had risen by an average of projected sea-level rise from 0.75 to 1.9 metres
3.3 millimetres per year between 1993 and 2006. relative to 1990, with 1.1–1.2 metres the midrange
of the projection.” And: “Current estimates of sea-
The worst-case scenario in the 2007 report, which
level rise range from 0.50 metre to over 2 metres by
looked mostly at thermal expansion of the oceans as
2100.”116
temperatures warmed, projected up to 0.59 metre of
sea-level rise by century’s end. In an extraordinary Yet extraordinarily, the 2014 IPCC assessment
verbal contortion, it then said it did “not assess report repeated the mistake and actually produced
the likelihood, nor provide a best estimate or an a numerically smaller figure (0.55 metre as
upper bound for sea-level rise… The projections do compared to 0.59 metre in 2007) despite mounting
not include uncertainties in climate–carbon cycle evidence of polar ice-mass loss: “Global mean sea-
feedbacks nor the full effects of changes in ice sheet level rise will continue during the 21st century, very
flow, therefore the upper values of the ranges are likely at a faster rate than observed from 1971 to
not to be considered upper bounds for sea-level 2010. For the period 2081–2100 relative to 1986–
rise. They include a contribution from increased 2005, the rise will likely be in the ranges of 0.26 to
Greenland and Antarctic ice flow at the rates 0.55 metre for RCP2.6, and of 0.45 to 0.82 metre
observed for 1993-2003, but this could increase or for RCP8.5.” And then, having noted estimates
decrease in the future.” for sea-level rise to 2100 of between 1.15 metres
and 2.4 metres, the report said: “Considering
Yet, in early 2007, Rahmstorf had presented a
this inconsistent evidence, we conclude that the
“semi-empirical relation… that connects global
probability of specific levels above the likely range
sea-level rise to global mean surface temperature”
cannot be reliably evaluated.” If some work
which resulted “in a projected sea-level rise in 2100
could not be “reliably evaluated”, how could they
of 0.5 to 1.4 meters above the 1990 level”.113
be sure of the much lower estimates that they
Many climate scientists received the 2007 IPCC had quantified?
report’s suggestion of a sea-level rise of 18–59
centimetres by 2100 with dismay, because it
seriously underestimated the problem. Even before
the 2007 report appeared, Hansen warned of
a “scientific reticence” which “in a case such as
ice-sheet instability and sea-level rise (results in) a
danger in excessive caution. We may rue reticence,
if it serves to lock in future disasters.”114
113 Rahmstorf 2007, op cit.
114 Hansen 2007, op cit.
115 Randerson, J 2008, ‘Sea level could rise by 150cm, US scientists warn’, The Guardian, 16 December 2008.
116 Australian Government, 2009, Climate Change Risks to Australia’s Coasts: A first pass national assessment, Australian Government, Canberra; CSIRO 2009,
Science Update 2009, no. 2, November 2009, Australian Government, Canberra.
What Lies Beneath 31
This event shot down any shreds of IPCC credibility Today the discussion amongst experts is for a
on sea-level rise that may have lingered after 2007. sea-level rise this century of at least one metre,
An updated NOAA sea-level rise report, released and perhaps in excess of two metres. The US
in August 2017, recommends a revised worst-case Department of Defence uses scenarios of one and
sea-level rise scenario of 2.5 metres by 2100, 5.5 two metres for risk assessments. Evidence (cited
metres by 2150 and 9.7 metres by 2200. It says above) that Antarctica by itself has the potential to
sea-level science has “advanced significantly over contribute more than a metre of sea-level rise by
the last few years, especially (for) land-based ice 2100, and that at 1°C of warming, West Antarctic
sheets in Greenland and Antarctica under global glaciers are in “unstoppable” meltdown for one-
warming”, and hence the “correspondingly larger to-four metres of sea-level rise, only add to grave
range of possible 21st century rise in sea level than concern that the IPCC reports are simply irrelevant
previously thought”. It points to “continued on this matter.
and growing evidence that both Antarctica and
Greenland are losing mass at an accelerated rate”,
which “strengthens an argument for considering
worst-case scenarios in coastal risk management”.117
Satellite Observations
6
4
IPCC
2 Projections
0
-2
Tide Gauges
-4
1970 1975 1980 1985 1990 1995 2000 2005 2010
Year
Figure 4: Observed sea-level rise 1970-2010 from tide gauge data (red) and satellite measurements (blue)
compared to model projections for 1990-2010 from the IPCC (grey band). (Source: The Copenhagen Diagnosis, 2009)
117 NOAA 2017, Global and regional sea-level rise scenarios for the United States, NOAA, Silver Spring MA.
What Lies Beneath 32
Y
NL
TO
“Political reality must be grounded in physical
reality or it’s completely useless.”
Prof. Hans Joachim Schellnhuber, 2009
AF
DR
What Lies Beneath 33
Y
NL
TO
UNDERSTATEMENT
AF
DR
What Lies Beneath 34
POLITICISATION
Much has been written about the inadequacy For example, the projected sea-level rise in the 2007
of IPCC processes, and the politicisation of its report was well below the subsequent observations.
decision-making. This occurred because scientists compiling the
Scientists say one reason the IPCC’s work is too report could not agree on how much would
conservative is that unwieldy processes mean be added to sea-level rise by melting polar ice
reports do not take the most recent research sheets, and so left out the data altogether to reach
into account. The cutoff point for science to “consensus”. Science historian Naomi Oreskes calls
be considered in a report is so far in advance this “consensus by omission”.119
of publication that the reports are out of date This is the consensus problem at the scientific level,
upon release. This is a crucial failure in a field of but there is also a problem at the political level. In
research that is rapidly changing. Inez Fung at the the first instance, the powerful coordinating authors
Berkeley Institute of the Environment, California for reports are selected by political representatives
says that for her research to be considered in the of the 195 member nations of the IPCC.
2007 IPCC report, she had to complete it by 2004. In the second instance, whilst the full-length IPCC
This is a typical experience that she identifies as Assessment Reports are compiled by scientists, the
“an awful lag in the IPCC process”.118 shorter and more widely reported SPMs require
IPCC Assessment Reports are compiled by working consensus from diplomats in “a painstaking, line-
groups of scientists within guidelines that urge the by-line revision by [political] representatives from
building of consensus conclusions from evidence more than 100 world governments — all of whom
presented, though that evidence itself may be must approve the final summary document”.120
diverse and sometimes contradictory in nature. As early as the IPCC’s first report in 1990,
The general result may be described as middle-of- the United States, Saudi Arabian and Russian
the-road reporting. Propositions supported by the delegations acted in “watering down the sense
greater quantity of research papers presented win of the alarm in the wording, beefing up the aura
out against propositions that might be outliers in of uncertainty”.121 Prof. Martin Parry of the UK
terms of quantity of papers presented, though the Met Office, co-chairman of an IPCC working
latter may be no less scientifically significant. group at the time, exposed the arguments between
The higher-impact possibilities may have less scientists and political officials over the 2007 IPCC
research available for consideration, but there are SPM: “Governments don’t like numbers, so some
good risk-management reasons for giving such numbers were brushed out of it.”122
possibilities more prominence, even if the event In 2014, The Guardian reported increasing evidence
probability is relatively low. that “the policy summaries on climate impacts and
mitigation by the IPCC were significantly ‘diluted’
under political pressure from some of the world’s
biggest greenhouse gas emitters, including Saudi
Arabia, China, Brazil and the United States”.123
118 Barras, C 2007, ‘Rocketing CO2 prompts criticisms of IPCC’, New Scientist, 24 October 2007.
119 Scherer 2012a, op cit.
120 Ibid.
121 Leggett, J 1999, The Carbon War: Global warming and the end of the oil era, Routledge, New York.
122 Adam, D 2007, ‘How climate change will affect the world’, The Guardian, 20 September 2007.
123 Ahmed, N 2014, ‘IPCC reports ‘diluted’ under ‘political pressure’ to protect fossil fuel interests’, The Guardian, 15 May 2014.
What Lies Beneath 35
One of the 2014 report’s more powerful sections “It may seem impossible to imagine that
was deleted during last minute negotiations over
the text. The section tried to specify other measures a technologically advanced society could
that would indicate whether we are entering a choose, in essence, to destroy itself, but
danger zone of profound climate impact, and just
how dramatic emissions cuts will have to be in that is what we are now in the process
order to avoid crossing that threshold. Prof. Michael of doing.”
Oppenheimer, an eminent climate scientist at
Elizabeth Kolbert, Field Notes from a Catastrophe, 2006
Princeton University who was also part of the core
writing team, suggests that politics got in the way.124
Oliver Gedden, head of the EU Research Division
at the German Institute for International and
Security Affairs in Berlin, says climate scientists and
economists who counsel policymakers are being
pressured to extend their models and options for
delivering mitigation later, which has “introduced
dubious concepts, such as repaying ‘carbon debt’
through ‘negative emissions’ to offset delayed
mitigation — in theory”.125 He says that climate
researchers who advise policymakers feel that they
have two options, to be pragmatic or be ignored:
“Many advisers are choosing pragmatism… Each
year, mitigation scenarios that explore policy
options for transforming the global economy
are more optimistic — and less plausible… The
scientific community must defend its independence
from outside interference.”126
124 Leggett, J 2014, ‘Why two crucial pages were left out of the latest UN climate report’, Jeremy Leggett, 4 November 2014, <http://www.jeremyleggett.
net/2014/11/why-two-crucial-pages-were-left-out-of-the-latest-u-n-climate-report/>.
125 Geden, O 2015, ‘Climate advisers must maintain integrity’, Nature, vol. 52, pp. 27-28.
126 ibid.
What Lies Beneath 36
GOALS ABANDONED
The IPCC and the UNFCCC are the twin climate The Paris voluntary national commitments
science and policy development organisations of would result in emissions in 2030 being higher
the UN. than in 2015 and are consistent with a 3.4°C
Conferences of the Parties (COPs) under warming path, and significantly higher if the
the UNFCCC are political fora, populated warming impacts of carbon-cycle feedbacks are
by professional representatives of national considered. Unless dramatically improved upon,
governments, and subject to the diplomatic the present commitments exclude the attainment
processes of negotiation, trade-offs and deals. In of either the 1.5°C or 2°C targets this century
this sense, the COPs are similar in process to that without wholly unrealistic assumptions about
of the IPCC by which the SPM are agreed by negative-emission technologies.
diplomats. The decision-making is inclusive (by The UNFCCC primary goal is to “stabilize
consensus), making outcomes hostage to national greenhouse gas concentrations in the atmosphere
interests and lowest-common-denominator politics. at a level that would prevent dangerous
The COP 21 Paris Agreement127 is almost devoid anthropogenic interference with the climate
of substantive language on the cause of human- system”.128 But what is “dangerous”? Traditionally,
induced climate change and contains no reference policymakers have focused on the 2°C target, but
to “coal”, “oil”, “fracking”, “shale oil”, “fossil the Paris Agreement emphasises “holding the increase
fuel” or “carbon dioxide”, nor to the words in the global average temperature to well below
“zero”, “ban”, “prohibit” or “stop”. By way of 2°C above pre-industrial levels and pursuing efforts
comparison, the term “adaptation” occurs more to limit the temperature increase to 1.5°C”.
than eighty times in 31 pages, though responsibility With the experience of global warming impacts
for forcing others to adapt is not mentioned, and so far, scientists have distinguished between
both liability and compensation are explicitly “dangerous” (1-2°C band) and “extremely
excluded. The Agreement has a goal but no firm dangerous” (above 2°C) climate warming.129
action plan, and bureaucratic jargon abounds, But we now have evidence that significant tipping
including the terms “enhance” and “capacity” points –– for example, summer sea-ice-free Arctic
appearing more than fifty times each. conditions, the loss of West Antarctic glaciers and
The proposed emission cuts by individual nations a multi-metre sea-level rise –– have very likely
under the Paris Agreement are voluntary (unilateral), been passed at less than 1°C of warming.130 As
without an enforceable compliance mechanism. well, evidence is accumulating that around the
In this sense, the Agreement cannot be considered current level of warming more elements of the
“binding” on signatories. The voluntary national system may be heading towards tipping points or
emission reduction commitments are not experiencing qualitative change. These include
critically analysed in the Agreement, but noted to be the slowing of the Thermohaline Circulation (the
inadequate for limiting warming to 2°C. Atlantic conveyor), likely as a result of climate
change; accelerating ice-mass loss from Greenland
and Antarctica; declining carbon efficiency of
the Amazon forests and other sinks; and the
vulnerability of Arctic permafrost stores. Warming
of 1.5°C would set sea-level rises in train sufficient
to challenge significant components of human
civilisation, besides reducing the world’s coral
ecosystems to remnant structures.
127 UN 2015, Paris Agreement, United Nations, New York, <http://unfccc.int/files/essential_background/convention/application/pdf/english_paris_
agreement.pdf>.
128 UNFCCC n.d., ‘First steps to a safer future: Introducing The United Nations Framework Convention on Climate Change’, United Nations, <http://
unfccc.int/essential_background/convention/items/6036.php>.
129 Anderson, K & Bows, A 2011 ‘Beyond ‘dangerous’ climate change: emission scenarios for a new world’, Philosophical Transactions of the Royal Society A vol.
369, pp. 20–44.
130 Livina & Lenton 2013, op. cit.; Rignot, Mouginot et al. 2014, op. cit.; DeConto & Pollard 2016, op. cit.
What Lies Beneath 37
In other words, climate change is already The UNFCCC key goals “to ensure that food
dangerous, but the UNFCCC processes have production is not threatened” and achieving
not acknowledged this reality, proposing higher “a time-frame sufficient to allow ecosystems
warming targets as policy goals. Nor has the IPCC to adapt naturally to climate change” have
process, with the lags in its publication process, and been discarded for all practical purposes. Food
a “burning embers” representation of the risks that production is already threatened by rising sea
again looks too conservative.131 levels and inundation, shifting rainfall patterns and
An expert panel recently concluded that warming desertification, and extreme heatwave and wildfire
would need to be limited to 1.2°C to save the episodes. Such events became a driver of the Arab
Great Barrier Reef.132 That is probably too Spring and a threat multiplier in the Syrian conflict
optimistic, but with a current warming trend of and in Darfur.133
about 1.1°C and 2016 global average warming Ecosystems, including coral reefs, mangroves and
above 1.2°C, it also demonstrates that climate kelp forests in Australia, are degrading fast as the
change is already dangerous. world’s sixth mass extinction gathers pace. Major
The question as to what would be safe for the ecosystems are now severely degraded and climate
protection of people and other species is not policymakers have no realistic agreement to save or
addressed by policymakers. restore them, from the Arctic to the Amazon, from
the Great Barrier Reef to the Sahel.
If climate change is already dangerous, then by
setting the 1.5°C and 2°C targets, the UNFCCC The Paris Agreement recognised the “fundamental
process has abandoned the goal of preventing priority of safeguarding food security” (note the
“dangerous anthropogenic influence with the change from the original goal to “ensure” food
climate system” for this century. production is not threatened). It made no reference
to earlier commitments to act within time-frames
sufficient to allow ecosystems to adapt naturally
to climate change, suggesting this goal has been
(literally) dropped.
131 O’Neill, B, Oppenheimer, M, Warren, R, Hallegatte, S, Kopp, RE, Portner, HO, Scholes, R, Birkmann, J, Foden, W, Mach, K, Marbaix, P, Mastrandrea,
M, Price, J, Takahashi, K, van Ypersele, JP & Yohe, G 2017, ‘IPCC reasons for concern regarding climate change risks’, Nature Climate Change, vol. 7, pp.
28–37.
132 Hannam, P 2017, ‘Warming limit of 1.2 degrees needed to save Great Barrier Reef: expert panel’, The Age, 2 August 2017.
133 Werrell, CE & Femia, F 2013, The Arab Spring and Climate Change, edn., Centre for American Progress/Stimson/The Center for Climate and Security,
Washington.
What Lies Beneath 38
A FAILURE OF
IMAGINATION
At the London School of Economics in 2008, This problem is widespread at senior levels of
Queen Elizabeth questioned: “Why did no one government and global corporations. A 2016
foresee the timing, extent and severity of the report, Thinking the Unthinkable (see page 9), based
Global Financial Crisis?” The British Academy on interviews with top leaders around the world,
answered a year later: “A psychology of denial found that: “A proliferation of ‘unthinkable’
gripped the financial and corporate world… [it events… has revealed a new fragility at the highest
was] the failure of the collective imagination of levels of corporate and public service leaderships.
many bright people… to understand the risks to Their ability to spot, identify and handle
the system as a whole.”134 unexpected, non-normative events is… perilously
A “failure of imagination” has also been identified inadequate at critical moments… Remarkably,
as one of the reasons for the breakdown in US there remains a deep reluctance, or what might be
intelligence around the 9/11 attacks in 2001. called ‘executive myopia’, to see and contemplate
even the possibility that ‘unthinkables’ might
Prof. Max Bazerman of Harvard University has
happen, let alone how to handle them.”136
asked why societies fail to implement wise strategies
to prevent “predictable surprises”, a term he coined Such failures are manifested in two ways in climate
to describe events that catch organisations and policy. At the political, bureaucratic and business
nations off-guard, despite necessary information levels in the underplaying of the high-end risks and
being available to anticipate the event. Bazerman in failing to recognise that the existential risks of
identifies five psychological patterns that help to climate change are totally different from other risk
explain the failure to act on climate: categories. And, at the research level, as embodied
in IPCC reports, in underestimating climate
“ … positive illusions lead us to conclude that a
change impacts, along with an under-emphasis on,
problem doesn’t exist or is not severe enough
and poor communication of, the high-end risks.
to merit action… we interpret events in an
The IPCC reports have not provided a sufficient
egocentric, or self-serving, manner… we overly
evidentiary base to answer a key question for
discount the future, despite our contentions that
normative policymaking: what would be safe?
we want to leave the world in good condition
As noted previously, IPCC processes paid little
for future generations… we try desperately to
attention to less than 2°C scenarios until prompted
maintain the status quo and refuse to accept
to do so by the political sector.
any harm, even when the harm would bring
about a greater good [and] we don’t want to Climate policymaking at all levels of government
invest in preventing a problem that we have not uses the reports of the IPCC as the primary
personally experienced or witnessed through physical science basis. The failure of the IPCC to
vivid data.”135 report in a balanced manner on the full range of
risks and to fully account for high-end outcomes
Bazerman suggests that many political leaders will leaves policymakers ill-informed. This undermines
not want to act until great, demonstrable harm has the capacity of governments and communities to
already occurred. make the correct decisions to protect their well-
being, or indeed to protect human civilisation as a
whole, in the face of existential risks.
134 Stewart, H 2009, ‘This is how we let the credit crunch happen, Ma’am …’, The Guardian, 26 July.
135 Bazerman, M 2006, ‘Climate change as a predictable surprise’, Climatic Change, vol. 77, pp. 179–193.
136 Gowing, N & Langdon, C 2016, op cit.
What Lies Beneath 39
ADDRESSING EXISTENTIAL
CLIMATE RISK
This report demonstrates the risk that both the speed counteracted by massive expansion of negative
and extent of future human-induced climate change emission technologies, such as carbon capture and
impacts has been badly underestimated. At the storage and BECCS — which do not even exist at
social level lies the massive inertia of global leaders, scale — in the second half of the century to draw
who still have great reluctance in accepting that their down excess carbon from the atmosphere. But, by
approach must fundamentally change if humanity, that time it will be too late to prevent irreversible,
and nature, are to have sustainable futures. catastrophic climate impacts.
The UNFCCC formally aims for climate policies In so doing, policymakers are complicit today in
which “enable economic development to proceed in destroying the very conditions which make
a sustainable manner”. In practice, priority is given human life possible. There is no greater crime
to short-term economic considerations. Thus the against humanity.
emphasis has been on ensuring that the emissions- After three decades of global inaction, climate
reduction paths developed for policymakers are not change is now an existential risk to humanity. It
economically disruptive. implies large negative consequences, which will be
For example, in 2006 and 2008 respectively, both irreversible, resulting in major reductions in global
Sir Nicholas Stern and Prof. Ross Garnaut, in and national population, mass species extinction,
their initial reports to the UK and Australian economic disruption and social chaos, unless carbon
governments, canvassed the 450 ppm and the emissions are rapidly reduced. The risk is immediate,
550 ppm atmospheric CO2 targets. Whilst both in that it is being locked in today by our insistence
concluded that 450 ppm would inflict significantly on expanding and sustaining the use of fossil fuels
less damage, they nevertheless advocated starting when the carbon budget to stay below sensible
with the 550 ppm figure because they considered temperature increase limits is already exhausted.
the lower goal would be too economically disruptive. As one of the countries most exposed to climate
(550 ppm is roughly equivalent to 3°C of warming impacts, and in the top half dozen carbon polluters
before carbon cycle feedbacks are considered, and worldwide when exports are included, this should be
truly devastating for people and nature). They have a major concern to Australia. Instead, it is ignored,
since acknowledged that evidence of accelerating with many parliamentarians refusing to even accept
climate impacts has rendered this approach that human-induced climate change is happening.
dangerously complacent.
In signing and ratifying the 2015 Paris Agreement, the
Rapid reduction of carbon emissions is still excluded global community, Australia included, committed
from consideration by policymakers because it is to the objectives of limiting global average
deemed to be too economically dislocating. The fact temperature increase to “well below 2°C above
that the present political path of 3°C or more of pre-industrial levels and to pursue efforts to limit the
warming would result in a world overwhelmed by increase to 1.5°C”, and “to reach global peaking
extreme climate impacts, leading to outright chaos, of greenhouse gas emissions as soon as possible, in
is avoided. The dominant neo-liberal framing of accordance with best available science”, recognising
progress, through globalisation and deregulation, that “climate change represents an urgent and
suppresses regulatory action which would address potentially irreversible threat to human societies
the real climate challenge because it undermines the and the planet”. To meet those objectives, climate
prevailing political–economic orthodoxy. action must be reframed around two principles:
Discussion around policy choices gives • Human-induced climate change represents an
primary emphasis to the role of markets. The immediate and existential threat to humanity; and
commodification of carbon pollution for the
• An emergency response is essential if that threat
purposes of market trading, and the virtue of carbon
is to be properly addressed.
pricing, are emphasised by policymakers as the most
desirable method for achieving decarbonisation. Such a response should seek to normatively achieve
However, these discussions have become unrealistic. these clearly defined objectives.
They accept the continuing expansion of fossil
fuels in the first half of the 21st century, eventually
What Lies Beneath 40
SUMMARY
Human-induced climate change is an existential This is a particular concern with potential climatic
risk to human civilisation: an adverse outcome that tipping points — passing critical thresholds which
will either annihilate intelligent life or permanently result in step changes in the climate system — such
and drastically curtail its potential, unless carbon as the polar ice sheets (and hence sea levels), and
emissions are rapidly reduced. permafrost and other carbon stores, where the
Special precautions that go well beyond impacts of global warming are non-linear and
conventional risk management practice are difficult to model with current scientific knowledge.
required if the increased likelihood of very large However the extreme risks to humanity, which
climate impacts — known as “fat tails” — are to be these tipping points represent, justify strong
adequately dealt with. The potential consequences precautionary management. Under-reporting on
of these lower-probability, but higher-impact, these issues is irresponsible, contributing to the
events would be devastating for human societies. failure of imagination that is occurring today in our
The bulk of climate research has tended to understanding of, and response to, climate change.
underplay these risks, and exhibited a preference If climate policymaking is to be soundly based,
for conservative projections and scholarly a reframing of scientific research within an
reticence, although increasing numbers of existential risk-management framework is now
scientists have spoken out in recent years on the urgently required. This must be taken up not just
dangers of such an approach. in the work of the IPCC, but also in the UNFCCC
Climate policymaking and the public narrative are negotiations if we are to address the real climate
significantly informed by the important work of the challenge.
IPCC. However, IPCC reports also tend toward Current processes will not deliver either the speed
reticence and caution, erring on the side of “least or the scale of change required.
drama”, and downplaying the more extreme and
more damaging outcomes.
Whilst this has been understandable historically,
given the pressure exerted upon the IPCC by
political and vested interests, it is now becoming
dangerously misleading with the acceleration
of climate impacts globally. What were lower-
probability, higher-impact events are now
becoming more likely.
REPORT AUTHORS
IAN DUNLOP DAVID SPRATT
Ian Dunlop is a senior member of the Advisory David Spratt is Research Director for Breakthrough
Board for Breakthrough. Ian was an international and co-author of Climate Code Red: The case for
oil, gas and coal industry executive, chairman emergency action. His recent work includes Recount: It’s
of the Australian Coal Association and chief time to ‘Do the math’ again, Climate Reality Check and
executive of the Australian Institute of Company Disaster Alley: Climate change, conflict and risk.
Directors. From 1998-2000 he chaired the
Australian Greenhouse Office Experts Group on
Emissions Trading. Ian is a member of the Club
of Rome.
Publication production by Luke Taylor. Design and layout by Christian Mendoza. Published by Breakthrough, National
Centre for Climate Restoration, Melbourne, Australia. First published September 2017. Revised and updated August 2018.
Breakthrough - National Centre for Climate Restoration is an independent body
developing critical thought leadership to influence the climate debate and policy making.
@breakthroughccr
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