Carbon Sequestration

Paleoreconstruction of estuarine sediments reveal human‐induced weakening of coastal carbon sinks

by Peter Macreadie

Global Change Biology (2012)
18: 891-901

Human activities in coastal areas frequently cause loss of benthic macrophytes (e.g. seagrasses) and concomitant... more Human activities in coastal areas frequently cause loss of benthic macrophytes (e.g. seagrasses) and concomitant increases in microalgal production through eutrophication. Whether such changes translate into shifts in the composition of sediment detritus is largely unknown, yet such changes could impact the role these ecosystems play in sequestrating CO2. We reconstructed the sedimentary records of cores taken from two sites within Botany Bay, Sydney – the site of European settlement of Australia – to look for human-induced changes in dominant sources of detritus in this estuary. Cores covered a period from the present day back to the middle Holocene (~6,000 y) according to 210Pb profiles and radiocarbon (14C) dating. Depositional histories at both sites couldn’t be characterized by a linear sedimentation rate; sedimentation rates in the last 30-50 years were considerably higher than during the rest of the Holocene. C:N ratios declined and began to exhibit a microalgal source signature from around the time of European settlement, which could be explained by increased nutrient flows into the Bay caused by anthropogenic activity. Analysis of stable isotopic ratios of 12C/13C showed that the relative contribution of seagrass and C3 terrestrial plants (mangroves, saltmarsh) to detritus declined around the time of rapid industrial expansion (~1950’s), coinciding with an increase in the contribution of microalgal sources. We conclude that the relative contribution of microalgae to detritus has increased within Botany Bay, and that this shift is the sign of increased industrialization and concomitant eutrophication. Given the lower carbon burial efficiencies of microalgae (~0.1%) relative to seagrasses and C3 terrestrial plants (up to 10%), such changes represent a substantial weakening of the carbon sink potential of Botany Bay – this occurrence is likely to be common to human-impacted estuaries, and has consequences for the role these systems play in helping to mitigate climate change.

Performance of CDM Afforestation in Tanzania (2011)

by Mark Purdon

Paper presented at THE 5TH ANNUAL MEETING OF THE ENVIRONMENT FOR DEVELOPMENT (EFD) INITIATIVE, Arusha, October 27-30, 2011

The research question motivating this research project is under what conditions do afforestation projects under the... more The research question motivating this research project is under what conditions do afforestation projects under the Clean Development Mechanism (CDM) of the Kyoto Protocol contribute significantly to sustainable rural development and generate genuine, additional carbon credits? This study provides answers to this question through a robust, comparative research design investigating CDM afforestation projects in Mufindi district, Tanzania. The afforestation projects were clearly having a positive direct impact on local employment and incomes. The observation that lands acquired for the CDM projects were unproductive lands allays concerns about food security. Furthermore, district government appeared to effectively verify that sufficient lands were retained by villages. In addition, the CDM project developer had been slow with meeting its commitments to provide social services, by at least 2008 it had begun to fulfill these obligations, including written commitment to dedicating 10% of carbon revenues to village development projects. There however remain biodiversity concerns due to the transformation away from grassland which need to be weighed against these direct economic benefits. Furthermore, the risks if the project fails to deliver continued economic development are significant given that the villages have lost title to former villages lands while review of compensation provided indicates this was extremely low. The additionality claims of the afforestation projects are however highly questionable. This is because the financial viability of the tree-planting changed over time in Mufindi district as a result of changing development conditions in Mufindi district as well as at the national level during the period 2005-2006. Trees planted for the CDM afforestation project can safely claim that carbon finance was necessary for project implementation, but becomes highly questionable afterward. This points to a need to devise a carbon accounting system to better accommodate changes in baselines over time.

Performance of CDM Afforestation in Moldova (2011)

by Mark Purdon

Paper presented at THE 5TH ANNUAL MEETING OF THE ENVIRONMENT FOR DEVELOPMENT (EFD) INITIATIVE, Arusha, October 27-30, 2011

The research question motivating this research project is under what conditions do afforestation projects under the... more The research question motivating this research project is under what conditions do afforestation projects under the Clean Development Mechanism (CDM) of the Kyoto Protocol contribute significantly to sustainable rural development and generate genuine, additional carbon credits? The primary goal of the current study is to answer this question through a robust, comparative research design of CDM afforestation projects in Moldova in Eastern Europe. The sustainable development claims of the two CDM afforestation projects are most significant in terms of restoration of degraded land—an ecosystem service of national importance. However, in terms of the socioeconomic development of the villages involved, the current impact of the projects appear modest. There were also significant problems with the institutional mechanism for allocating lands for afforestation which have resulted in tension, if not conflict, in a number of villages involved. This is due to a lack of appropriate mechanisms to allow villagers to effectively participate in decisions made by village councils. Villages already have significant rights over the use of village lands that Moldsilva, the state forest agency, and district authorities respected. The CDM afforestation projects in Moldova appeared highly additional (particularly in the short-term), leading to a more than doubling of afforestation effort than Moldsilva would have been able to muster independently. Two elements help to explain the additionality of the CDM afforestation projects. Most important, has been the motivation for afforestation, which has been political rather than financial. At the same time, there was a latent institutional infrastructure in place that was able to respond effectively once the CDM made resources available for afforestation.

Warming alters the metabolic balance of ecosystems

by Gabriel Yvon-Durocher

The carbon cycle modulates climate change, via the regulation of atmospheric CO2, and it represents one of the most... more The carbon cycle modulates climate change, via the regulation of atmospheric CO2, and it represents one of the most important services provided by ecosystems. However, considerable uncertainties remain concerning potential feedback between the biota and the climate. In particular, it is unclear how global warming will affect the metabolic balance between the photosynthetic fixation and respiratory release of CO2 at the ecosystem scale. Here, we present a combination of experimental field data from freshwater mesocosms, and theoretical predictions derived from the metabolic theory of ecology to investigate whether warming will alter the capacity of ecosystems to absorb CO2. Our manipulative experiment simulated the temperature increases predicted for the end of the century and revealed that ecosystem respiration increased at a faster rate than primary production, reducing carbon sequestration by 13 per cent. These results confirmed our theoretical predictions based on the differential activation energies of these two processes. Using only the activation energies for whole ecosystem photosynthesis and respiration we provide a theoretical prediction that accurately quantified the precise magnitude of the reduction in carbon sequestration observed experimentally. We suggest the combination of whole-ecosystem manipulative experiments and ecological theory is one of the most promising and fruitful research areas to predict the impacts of climate change on key ecosystem services.

The Temperature Dependence of the Carbon Cycle in Aquatic Ecosystems

by Gabriel Yvon-Durocher

The carbon cycle modulates climate change via the regulation of atmospheric CO2, and represents one of the most... more The carbon cycle modulates climate change via the regulation of atmospheric CO2, and represents one of the most important ecosystem services of value to humans. However, considerable uncertainties remain concerning potential feedbacks between the biota and the climate. We developed theoretical models
derived from the metabolic theory of ecology (MTE), and tested them in an ecosystem-level manipulative experiment in freshwater mesocosms. The yearlong experiment simulated a warming scenario (A1B; [IPCC, 2007]) expected by the end of the century. The key components of the carbon cycle – that is gross primary production (GPP), ecosystem respiration (ER) and CH4 efflux (ME) – measured in our experiment were all strongly related to temperature. Their temperature dependence was typically constrained by the average activation energy of their particular metabolic pathway, and as predicted by our models, this increased progressively for GPP, ER and ME. Warming of 4°C decreased the sequestration of CO2 by 13%, increased the fraction of primary production effluxing as methane by 20% and the fraction of ER as methane by 9%, in line with the offset in their respective activation energies. Because methane has 21 times the greenhouse gas radiative potential of CO2, these results suggest aquatic ecosystems could drive a previously unknown positive feedback between warming and the carbon cycle.

We then used a series of global data compilations of measurements of rates of primary production and respiration to better understand the temperature dependence of the carbon cycle in other aquatic ecosystems and to compare them with data from terrestrial systems. Our experimental results were mirrored by our global data compilations, with the effective activation energy for marine and freshwater primary production identical to GPP measured in our experiment. Similarly, the temperature dependences of respiration in estuaries, lakes and the ocean were indistinguishable from that of ER in our experiment. Finally, our study suggests that the temperature dependence of primary production and respiration in aquatic ecosystems might differ from those in terrestrial ecosystems, and this could be crucial in predicting the future response of the carbon cycle in these different systems to global warming.

Warming increases the proportion of primary production emitted as methane from freshwater mesocosms

by Gabriel Yvon-Durocher

Methane (CH4) and carbon dioxide (CO2) are the dominant gaseous end products of the remineralization of organic carbon... more Methane (CH4) and carbon dioxide (CO2) are the dominant gaseous end products of the remineralization of organic carbon and also the two largest contributors to the anthropogenic greenhouse effect. We investigated whether warming altered the balance of CH4 efflux relative to gross primary production (GPP) and ecosystem respiration (ER) in a freshwater mesocosm experiment. Whole ecosystem CH4 efflux was strongly related to temperature with an apparent activation energy of 0.85 eV. Furthermore, CH4 efflux increased faster than ER or GPP with temperature, with all three processes having sequentially lower activation energies. Warming of 4C increased the fraction of GPP effluxing as CH4 by 20% and the fraction of ER as CH4 by 9%, in line with the offset in their respective activation energies. Because CH4 is 21 times more potent as a greenhouse gas, relative to CO2, these results suggest freshwater ecosystems could drive a previously unknown positive feedback between warming and the carbon cycle.

Consistent temperature dependence of respiration across ecosystems contrasting in thermal history

by Gabriel Yvon-Durocher

Ecosystem respiration is a primary component of the carbon cycle and understanding the mechanisms that determine its... more Ecosystem respiration is a primary component of the carbon cycle and understanding the mechanisms that determine its temperature dependence will be important for predicting how rates of carbon efflux might respond to global warming. We used a rare model system, comprising a network of geothermally heated streams ranging in temperature from 5 °C to 25 °C, to explore the nature of the relationship between respiration and temperature. Using this ‘natural experiment’, we tested whether the natal thermal regime of stream communities influenced the temperature dependence of respiration in the absence of other potentially confounding variables. An empirical survey of 13 streams across the thermal gradient revealed that the temperature dependence of whole-stream respiration was equivalent to the average activation energy of the respiratory complex (0.6–0.7 eV). This observation was also consistent for in-situ benthic respiration. Laboratory experiments, incubating biofilms from four streams across the thermal gradient at a range of temperatures, revealed that the activation energy and Q10 of respiration were remarkably consistent across streams, despite marked differences in their thermal history and significant turnover in species composition. Furthermore, absolute rates of respiration at standardised temperature were also unrelated to ambient stream temperature, but strongly reflected differences in biofilm biomass. Together, our results suggest that the core biochemistry,which drives the kinetics of oxidative respiratory metabolism, may be well conserved among diverse taxa and environments, and that the intrinsic sensitivity of respiration to temperature is not influenced by ambient environmental temperature.

Carbon and forests: The big picture

by Jerome Vanclay

Vanclay, J., 2011. Carbon and forests: The big picture. Australasian Science 32(10):4.

Energy generated by burning forestry waste and other biomass sources should be recognised as renewable. Energy generated by burning forestry waste and other biomass sources should be recognised as renewable.

Ninsei, Plant Patent Variety

by A Nonomura

Photosynthetically grow gasoline type hydrocarbons in patented plant variety "Ninsei" Photosynthetically grow gasoline type hydrocarbons in patented plant variety "Ninsei"

Carbon Sequestration to Generate Calcium Carbonate A Practical Approach to Sequester Residential CO2 Exhaust

by Ravi Dinakar

For FREE full pdf visit:

http://www.jes2s.com/pdfs/Jan2012/Carbon%20Sequestration%20to%20Generate%20Calcium%20Carbonate%20A%20Practical%20Approach%20to%20Sequester%20Residential%20CO2%20Exhaust.pdf

Authors:

Jeremy Wortzel1* and Terese Grateful2
Student1, Teacher2: Council Rock High School North, 62 Swamp Rd, Newtown, PA 18940
Program Advisor: Jeffery Field, PhD, University of Pennsylvania Department, TREES Program
*Correspondence: jdwortzel@gmail.com

Published in The Journal of Experimental Secondary Science (www.jes2s.com)

The sequestration of carbon dioxide (CO2) from fossil
fuel exhaust can reduce greenhouse gas emissions thatmore The sequestration of carbon dioxide (CO2) from fossil
fuel exhaust can reduce greenhouse gas emissions that
contribute to global warming. Current methods of CO2
sequestration have multiple steps, are expensive, and
potentially hazardous. In contrast, lime water sequesters
CO2 to generate calcium carbonate (CaCO3) in a one-step
process, producing a safe product that has many industrial
applications. A laboratory model was designed to explore
the potential of lime water to sequester CO2 from residential
furnace exhaust. The quantity of CO2 sequestered
and CaCO3 generated by lime water was theoretically
calculated. Lime water, made from calcium hydroxide, was
used to sequester CO2 from dry ice. The average amount
of CaCO3 generated was 0.90 g/L lime water, which was
statistically similar to the predicted value of 1.05 g/L lime
water (p = 0.20). The experimental yield was 86%, and the
quantity of CO2 sequestered was 0.40 g/L lime water. The
volume of lime water required to sequester CO2 from the
average American home furnace was determined, and a
household sequestration apparatus was designed. This
study supports the potential to utilize lime water as a novel
approach to sequester CO2 from home furnace exhaust,
and in turn aid in reversing global warming.

XXVIII

by A Nonomura

Co-authored with Andrew A. Benson and Barry A. Cullen
Published in Advances in Photosynthesis, 2012, Intech, ISBN 978-953-307-928-8

Contaminant mobility and carbon sequestration downstream of the Ajka (Hungary) red mud spill: The effects of gypsum dosing

by William Mayes

Science of the Total Environment

A number of emergency pollution management measures were enacted after the accidental release of caustic bauxite... more A number of emergency pollution management measures were enacted after the accidental release of caustic bauxite processing residue that occurred in Ajka, western Hungary in October, 2010. These centred on acid and gypsum dosing to reduce pH and minimise mobility of oxyanion contaminants mobile at high pH. This study assessed the effectiveness of gypsum dosing on contaminant mobility and carbon sequestration through assessment of red mud and gypsum-affected fluvial sediments via elemental analysis and stable isotope analysis. There was a modest uptake of contaminants (notably As, Cr, and Mn) on secondary carbonate-dominated deposits in reaches subjected to gypsum dosing. C and O stable isotope ratios of carbonate precipitates formed as a result of gypsum dosing were used to quantify the importance of the neutralisation process in sequestering atmospheric carbon dioxide. This process was particularly pronounced at sites most affected by gypsum addition, where up to 36% of carbonate-C appears to be derived from atmospheric in-gassing of CO2. The site is discussed as a large scale analogue for potential remedial approaches and carbon sequestration technologies that could be applied to red mud slurries and other hyperalkaline wastes. The results of this work have substantial implications for the aluminium production industry in which 3–4% of the direct CO2 emissions may be offset by carbonate precipitation. Furthermore, carbonation by gypsum addition may be important for contaminant remediation, also providing a physical stabilisation strategy for the numerous historic stockpiles of red mud.

The Path of Carbon in Photosynthesis. XXVIII

by A Nonomura

Andrew A. Benson
Part 3, The Path of Carbon in Photosynthesis.
Chapter 13, Advances in Photosynthesis-Fundamental Aspects, InTech

Benson Calvin Cycle Benson Calvin Cycle

Amazonian Dark Earths as carbon stores and sinks

by Philip Fearnside

Comentários sobre o Projeto FLORAM

by Philip Fearnside

Fearnside, P.M. 1990. Comentários sobre o Projeto FLORAM. estudos AVANÇADOS 4(9): 288-289.

Biomass of Brazil's Amazonian forests: Reply to Brown and Lugo revisited

by Philip Fearnside

, P.M. 1993. Biomass of Brazil's Amazonian forests: Reply to Brown and Lugo revisited. Interciencia 18(1): 5-7.

See Amazon Controveersies:
http://philip.inpa.gov.br/publ_livres/AMAZONIAN CONTROVERSIES.htm

Comment on:'Burning management and carbon sequestration of upland heather moorland in the UK'

by G. Matt Davies

The future of fire management in the British uplands

by G. Matt Davies

Status of carbon sequestration projects in Africa

by Rohit Jindal

Lammers, K. et al., 2011. CO2 sequestration through mineral carbonation of iron oxyhydroxides. Environmental Science & Technology, 45: 10422–10428.

by Martin Schoonen

ABSTRACT: Carbon dioxide sequestration via the use of
sulfide reductants and mineral carbonation of the iron... more ABSTRACT: Carbon dioxide sequestration via the use of
sulfide reductants and mineral carbonation of the iron oxyhydr-
oxide polymorphs lepidocrocite, goethite, and akaganeite with
supercritical CO2 (scCO2) was investigated using in situ atte-
nuated total reflection Fourier transform infrared spectroscopy
(ATR-FTIR), X-ray diffraction (XRD), and transmission elec-
tron microscopy (TEM). The exposure of the different iron
oxyhydroxides to aqueous sulfide in contact with scCO2 at
∼70