Search Results
Author(s): Russell LM, Rasch PJ, Mace GM, Jackson RB, Shepherd JG, Liss PS, Leinen MS, Schimel D, Vaughan NE, Janetos AC, Boyd PW, Norby RJ, Caldeira K, Merikanto J, Artaxo P, Melillo J, Morgan MG
Published: March, 2012
Publisher: Ambio
DOI: 10.1007/s13280-012-0258-5
Tags: Research, Biodiversity
URL: http://www.springerlink.com/content/u562q0218461k416/
Abstract: Geoengineering methods are intended to reduce climate change, which is already having demonstrable effects on ecosystem structure and functioning in some regions. Two types of geoengineering activities that have been proposed are: carbon dioxide (CO(2)) removal (CDR), which removes CO(2) from the atmosphere, and solar radiation management (SRM, or sunlight reflection methods), which reflects a small percentage of sunlight back into space to offset warming from greenhouse gases (GHGs). Current research suggests that SRM or CDR might diminish the impacts of climate change on ecosystems by reducing changes in temperature and precipitation. However, sudden cessation of SRM would exacerbate the climate effects on ecosystems, and some CDR might interfere with oceanic and terrestrial ecosystem processes. The many risks and uncertainties associated with these new kinds of purposeful perturbations to the Earth system are not well understood and require cautious and comprehensive research.
Author(s): Ricke KL, Rowlands DJ, Ingram WJ, Keith DW, Morgan MG
Published: December, 2011
Publisher: Nature Climate Change
DOI: 10.1038/nclimate1328
Tags: Stratospheric Aerosols, Climate Modelling
URL: http://www.nature.com/nclimate/journal/v2/n2/full/nclimate1328.html
Abstract: If implementation of proposals to engineer the climate through solar-radiation management (SRM) ever occurs, it is likely to be contingent on climate sensitivity. However, modelling studies examining the effectiveness of SRM as a strategy to offset anthropogenic climate change have used only the standard parameterizations of atmosphere–ocean general circulation models that yield climate sensitivities close to the Coupled Model Intercomparison Project mean. Here, we use a perturbed-physics ensemble modelling experiment to examine how the response of the climate to SRM implemented in the stratosphere (SRM-S) varies under different greenhouse-gas climate sensitivities. When SRM-S is used to compensate for rising atmospheric concentrations of greenhouse gases, its effectiveness in stabilizing regional climates diminishes with increasing climate sensitivity. However, the potential of SRM-S to slow down unmitigated climate change, even regionally, increases with climate sensitivity. On average, in variants of the model with higher sensitivity, SRM-S reduces regional rates of temperature change by more than 90% and rates of precipitation change by more than 50%.
Author(s): Long JCS, Rademaker S, Anderson JG, Benedick R, Caldeira K, Chaisson J, Goldson D, Hamburg SP, Keith DW, Lehman R, Lowy F, Morgan MG, Sarewitz D, Schelling TC, Shepherd JG, Victor DG, Welan D, Winickoff DE
Published: October, 2011
Publisher: Bipartisan Policy Center
Tags: Overview, Research, Policy
URL: http://www.bipartisanpolicy.org/library/report/task-force-climate-remediation-research
Abstract: This report presents the conclusions of the Task Force on Climate Remediation Research, which was convened by the nonprofit Bipartisan Policy Center in March 2010 to develop recommendations for the U.S. government concerning geoengineering research and oversight policy. Participants included leaders from the scientific, science policy, foreign policy, national security, legal, and environmental communities who together brought a wide range of perspectives and expertise to the task force.
Author(s): Ricke KL, Morgan MG, Allen MR
Published: July, 2010
Publisher: Nature Geoscience
DOI: 10.1038/ngeo915
Tags: Stratospheric Aerosols, Environmental Side-Effects, Precipitation,
URL: http://www.nature.com/ngeo/journal/v3/n8/full/ngeo915.html
Abstract: Concerns about the slow pace of climate mitigation have led to renewed dialogue about solar-radiation management, which could be achieved by adding reflecting aerosols to the stratosphere. Modelling studies suggest that solar-radiation management could produce stabilized global temperatures and reduced global precipitation. Here we present an analysis of regional differences in a climate modified by solar-radiation management, using a large-ensemble modelling experiment that examines the impacts of 54 scenarios for global temperature stabilization. Our results confirm that solar-radiation management would generally lead to less extreme temperature and precipitation anomalies, compared with unmitigated greenhouse gas emissions. However, they also illustrate that it is physically not feasible to stabilize global precipitation and temperature simultaneously as long as atmospheric greenhouse gas concentrations continue to rise. Over time, simulated temperature and precipitation in large regions such as China and India vary significantly with different trajectories for solar-radiation management, and they diverge from historical baselines in different directions. Hence, it may not be possible to stabilize the climate in all regions simultaneously using solar-radiation management. Regional diversity in the response to different levels of solar-radiation management could make consensus about the optimal level of geoengineering difficult, if not impossible, to achieve.
Author(s): Morgan MG, Ricke KL
Published: January, 2010
Publisher: International Risk Governance Council
URL: http://www.irgc.org/IMG/pdf/SRM_Opinion_Piece_web.pdf
Abstract: The authors begin this Opinion Piece by outlining the basic science that underlies the climate problem. They explain that when fossil fuels (i.e., coal, oil and natural gas) are burned, CO2 is released to the atmosphere, where much of it remains for 100 years or more. CO2 traps heat with the result that the planet warms, causing changes in the climate. The magnitude of these changes can be reduced if the concentration of CO2 in the atmosphere is lowered. To avoid a significantly changed and warmer climate, as well as the other impacts of rising levels of CO2, the world needs to achieve roughly an 80% reduction in emissions of CO2. The authors outline a number of ways in which this might be done. All of these strategies to reduce the concentration of CO2 in the atmosphere are relatively slow (decades to centuries) and expensive (perhaps 0.5% to 5% of world GDP). In contrast, if the fraction of sunlight reflected by the earth back into space (the albedo) is slightly increased, then the amount of sunlight that is absorbed by the earth system is slightly reduced and the planet is cooled. This can occur very rapidly – requiring only days to months. Large explosive volcanic eruptions clearly demonstrate this when they add large amounts of fine reflective particles to the stratosphere. Humans could do similar things to increase albedo, perhaps at a cost that is 1/100th or less of the cost of reducing the level of CO2 in the atmosphere. Such activities are called “solar radiation management” or SRM. Trying to intentionally and rapidly modify the earth’s climate strikes many people as a bad idea. While SRM may be relatively cheap and fast, it is also imperfect. It cannot precisely offset warming. It would lead to changes in the levels and patterns of precipitation and it would do nothing to offset the negative ecological effects of rising levels of CO2 in the atmosphere, in particular the ongoing acidification of the world’s oceans, which will likely result in the demise of most corals and many other ocean ecosystems by the end of this century. The world has been talking about reducing emissions for decades and has yet to make significant reductions. The authors argue that in order to be prepared in the event of a “climate emergency”, or for the case where someone tries to undertake SRM unilaterally, the time has come for a research programme on SRM that examines: how it might be done; what it would cost; and what intended and unintended impacts and risks might arise. They call on the research community to define a set of limits within which modest low-level field research could be conducted with minimal impact and therefore without formal international approval. They argue that any such research should be open, transparent and loosely coordinated internationally. In parallel with this research, they call for an effort to engage the foreign policy community in discourse to identify and assess the strengths and limitations of alternative possible approaches to the global governance of SRM.
Author(s): Keith DW, Parson EA, Morgan MG
Published: January, 2010
Publisher: Nature
DOI: 10.1038/463426a
Tags: Research, Stratospheric Aerosols, Moral Hazard
URL: http://www.nature.com/nature/journal/v463/n7280/full/463426a.html
Abstract: Geoengineering studies of solar-radiation management should begin urgently, argue David W. Keith, Edward Parson and M. Granger Morgan — before a rogue state decides to act alone. Summary: 1) Field testing is required to understand the risks of solar-radiation management (SRM); 2) Linked activities must create norms and understanding for international governance of SRM; 3) If SRM is unworkable, the sooner we know, the less moral hazard it poses.
Author(s): Morgan MG
Published: January, 2010
Publisher: Technology Review MIT
Tags: Research
URL: http://www.technologyreview.com/energy/24174/
Abstract: Scientists already know how to cool the planet quickly. The secret is geoengineering: specifically, using very fine particles in the stratosphere to reflect sunlight (see "The Geoengineering Gambit"). The direct cost of shading the planet this way could be less than a few hundredths the cost of reducing carbon dioxide emissions. If reflecting sunlight is fast and cheap, why struggle with all the problems of collective action to achieve emission reductions? Why not wait until we have a climate problem and then simply fix it?
Author(s): Victor DG, Morgan MG, Apt J, Steinbruner J, Ricke KL
Published: March, 2009
Publisher: Foreign Affairs
Tags: Politics
Abstract: Global warming is accelerating, and although engineering the climate strikes most people as a bad idea, it is time to take it seriously.
Author(s): Wilson EJ, Morgan MG, Apt J, Bonner M, Bunting C, Gode J, Haszeldine RS, Jaeger CC, Keith DW, Mccoy ST, Pollak MF, Reiner DM, Rubin ES, Torvanger A, Ulardic C, Vajjhala SP, Victor DG, Wright IW
Published: April, 2008
Publisher: Environmental Science & Technology
DOI: 10.1021/es087037k
Tags: Law, Terrestrial Carbon Storage
URL: http://pubs.acs.org/doi/abs/10.1021/es087037k?
Abstract: Governments worldwide should provide incentives for initial large-scale GS projects to help build the knowledge base for a mature, internationally harmonized GS regulatory framework. Health, safety, and environmental risks of these early projects can be managed through modifications of existing regulations in the EU, Australia, Canada, and the U.S. An institutional mechanism, such as the proposed Federal Carbon Sequestration Commission in the U.S., should gather data from these early projects and combine them with factors such as GS industrial organization and climate regime requirements to create an efficient and adaptive regulatory framework suited to large-scale deployment. Mechanisms to structure long-term liability and fund long-term postclosure care must be developed, most likely at the national level, to equitably balance the risks and benefits of this important climate change mitigation technology. We need to do this right. During the initial field experiences, a single major accident, resulting from inadequate regulatory oversight, anywhere in the world, could seriously endanger the future viability of GS. That, in turn, could make it next to impossible to achieve the needed dramatic global reductions in CO2 emissions over the next several decades. We also need to do it quickly. Emissions are going up, the climate is changing, and impacts are growing. The need for safe and effective CO2 capture with deep GS is urgent.
Author(s): Morgan MG, Adams PJ, Keith DW
Published: April, 2006
Publisher: Climatic Change
DOI: 10.1007/s10584-005-9025-y
Tags: Tropospheric Aerosols, Uncertainty
URL: http://www.ingentaconnect.com/content/klu/clim/2006/00000075/F0020001/00009025
Abstract: A group of twenty-four leading atmospheric and climate scientists provided subjective probability distributions that represent their current judgment about the value of planetary average direct and indirect radiative forcing from anthropogenic aerosols at the top of the atmosphere. Separate estimates were obtained for the direct aerosol effect, the semi-direct aerosol effect, cloud brightness (first aerosol indirect effect), and cloud lifetime/distribution (second aerosol indirect effect). Estimates were also obtained for total planetary average forcing at the top of the atmosphere and for surface forcing. Consensus was strongest among the experts in their assessments of the direct aerosol effect and the cloud brightness indirect effect. Forcing from the semi-direct effect was thought to be small (absolute values of all but one of the experts' best estimates were ≤0.5 W/m2). There was not agreement about the sign of the best estimate of the semi-direct effect, and the uncertainty ranges some experts gave for this effect did not overlap those given by others. All best estimates of total aerosol forcing were negative, with values ranging between −0.25 W/m2 and −2.1 W/m2. The range of uncertainty that a number of experts associated with their estimates, especially those for total aerosol forcing and for surface forcing, was often much larger than that suggested in 2001 by the IPCC Working Group 1 summary figure (IPCC, 2001).