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Lawrence MG, Schäfer S, Muri H, Scott V, Oschlies A, Vaughan NE, Boucher O, Schmidt H, Haywood J, Scheffran J. Evaluating climate geoengineering proposals in the context of the Paris Agreement temperature goals. Nat Commun 2018; 9:3734. [PMID: 30213930 PMCID: PMC6137062 DOI: 10.1038/s41467-018-05938-3] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 08/07/2018] [Indexed: 11/11/2022] Open
Abstract
Current mitigation efforts and existing future commitments are inadequate to accomplish the Paris Agreement temperature goals. In light of this, research and debate are intensifying on the possibilities of additionally employing proposed climate geoengineering technologies, either through atmospheric carbon dioxide removal or farther-reaching interventions altering the Earth’s radiative energy budget. Although research indicates that several techniques may eventually have the physical potential to contribute to limiting climate change, all are in early stages of development, involve substantial uncertainties and risks, and raise ethical and governance dilemmas. Based on present knowledge, climate geoengineering techniques cannot be relied on to significantly contribute to meeting the Paris Agreement temperature goals. Research and debate are intensifying on complementing CO2 emissions reductions with hypothetical climate geoengineering techniques. Here, the authors assess their potentials, uncertainties and risks, and show that they cannot yet be relied on to significantly contribute to meeting the Paris Agreement temperature goals.
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Affiliation(s)
- Mark G Lawrence
- Institute for Advanced Sustainability Studies (IASS), Potsdam, Germany. .,University of Potsdam, Potsdam, Germany.
| | - Stefan Schäfer
- Institute for Advanced Sustainability Studies (IASS), Potsdam, Germany.,Institute for Science, Innovation and Society, University of Oxford, Oxford, UK
| | - Helene Muri
- University of Oslo, Oslo, Norway.,Norwegian University of Science and Technology, Trondheim, Norway
| | | | | | | | - Olivier Boucher
- Institut Pierre-Simon Laplace, CNRS / Sorbonne Université, Paris, France
| | - Hauke Schmidt
- Max Planck Institute for Meteorology, Hamburg, Germany
| | - Jim Haywood
- University of Exeter, Exeter, UK.,Met Office Hadley Centre, Exeter, UK
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Keller DP, Lenton A, Littleton EW, Oschlies A, Scott V, Vaughan NE. The Effects of Carbon Dioxide Removal on the Carbon Cycle. Curr Clim Change Rep 2018; 4:250-265. [PMID: 30956937 PMCID: PMC6428234 DOI: 10.1007/s40641-018-0104-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Increasing atmospheric CO2 is having detrimental effects on the Earth system. Societies have recognized that anthropogenic CO2 release must be rapidly reduced to avoid potentially catastrophic impacts. Achieving this via emissions reductions alone will be very difficult. Carbon dioxide removal (CDR) has been suggested to complement and compensate for insufficient emissions reductions, through increasing natural carbon sinks, engineering new carbon sinks, or combining natural uptake with engineered storage. Here, we review the carbon cycle responses to different CDR approaches and highlight the often-overlooked interaction and feedbacks between carbon reservoirs that ultimately determines CDR efficacy. We also identify future research that will be needed if CDR is to play a role in climate change mitigation, these include coordinated studies to better understand (i) the underlying mechanisms of each method, (ii) how they could be explicitly simulated, (iii) how reversible changes in the climate and carbon cycle are, and (iv) how to evaluate and monitor CDR.
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Affiliation(s)
- David P. Keller
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany
| | - Andrew Lenton
- CSIRO Oceans and Atmosphere, Hobart, Australia
- Antarctic Climate and Ecosystems Cooperative Research Centre, Hobart, Australia
| | - Emma W. Littleton
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Andreas Oschlies
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany
| | - Vivian Scott
- School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | - Naomi E. Vaughan
- Tyndall Centre for Climate Change Research, School of Environmental Sciences, University of East Anglia, Norwich, UK
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Bellamy R, Chilvers J, Vaughan NE. Deliberative Mapping of options for tackling climate change: Citizens and specialists 'open up' appraisal of geoengineering. Public Underst Sci 2016; 25:269-86. [PMID: 25224904 PMCID: PMC4819797 DOI: 10.1177/0963662514548628] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Appraisals of deliberate, large-scale interventions in the earth's climate system, known collectively as 'geoengineering', have largely taken the form of narrowly framed and exclusive expert analyses that prematurely 'close down' upon particular proposals. Here, we present the findings from the first 'upstream' appraisal of geoengineering to deliberately 'open up' to a broader diversity of framings, knowledges and future pathways. We report on the citizen strand of an innovative analytic-deliberative participatory appraisal process called Deliberative Mapping. A select but diverse group of sociodemographically representative citizens from Norfolk (United Kingdom) were engaged in a deliberative multi-criteria appraisal of geoengineering proposals relative to other options for tackling climate change, in parallel to symmetrical appraisals by diverse experts and stakeholders. Despite seeking to map divergent perspectives, a remarkably consistent view of option performance emerged across both the citizens' and the specialists' deliberations, where geoengineering proposals were outperformed by mitigation alternatives.
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Vaughan NE, Lenton TM. Interactions between reducing CO2 emissions, CO2 removal and solar radiation management. Philos Trans A Math Phys Eng Sci 2012; 370:4343-4364. [PMID: 22869802 DOI: 10.1098/rsta.2012.0188] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We use a simple carbon cycle-climate model to investigate the interactions between a selection of idealized scenarios of mitigated carbon dioxide emissions, carbon dioxide removal (CDR) and solar radiation management (SRM). Two CO(2) emissions trajectories differ by a 15-year delay in the start of mitigation activity. SRM is modelled as a reduction in incoming solar radiation that fully compensates the radiative forcing due to changes in atmospheric CO(2) concentration. Two CDR scenarios remove 300 PgC by afforestation (added to vegetation and soil) or 1000 PgC by bioenergy with carbon capture and storage (removed from system). Our results show that delaying the start of mitigation activity could be very costly in terms of the CDR activity needed later to limit atmospheric CO(2) concentration (and corresponding global warming) to a given level. Avoiding a 15-year delay in the start of mitigation activity is more effective at reducing atmospheric CO(2) concentrations than all but the maximum type of CDR interventions. The effects of applying SRM and CDR together are additive, and this shows most clearly for atmospheric CO(2) concentration. SRM causes a significant reduction in atmospheric CO(2) concentration due to increased carbon storage by the terrestrial biosphere, especially soils. However, SRM has to be maintained for many centuries to avoid rapid increases in temperature and corresponding increases in atmospheric CO(2) concentration due to loss of carbon from the land.
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Affiliation(s)
- Naomi E Vaughan
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
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Russell LM, Rasch PJ, Mace GM, Jackson RB, Shepherd J, Liss P, Leinen M, Schimel D, Vaughan NE, Janetos AC, Boyd PW, Norby RJ, Caldeira K, Merikanto J, Artaxo P, Melillo J, Morgan MG. Ecosystem impacts of geoengineering: a review for developing a science plan. Ambio 2012; 41:350-69. [PMID: 22430307 PMCID: PMC3393062 DOI: 10.1007/s13280-012-0258-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 09/27/2011] [Accepted: 01/31/2012] [Indexed: 05/22/2023]
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.
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Affiliation(s)
- Lynn M. Russell
- Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Dr. Mail Code 0221, La Jolla, CA 92093-0221 USA
| | - Philip J. Rasch
- Pacific Northwest National Laboratory, 902 Battelle Boulevard, P. O. Box 999, MSIN K9-34, Richland, WA 99352 USA
| | - Georgina M. Mace
- Centre for Population Biology, Imperial College London, Ascot, Berks SL5 7PY UK
| | - Robert B. Jackson
- Nicholas School of the Environment, Duke University, Durham, NC 27708 USA
| | - John Shepherd
- Earth System Science, School of Ocean and Earth Sciences, National Oceanography Centre, University of Southampton, European Way, Southampton, SO14 3ZH UK
| | - Peter Liss
- School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ UK
| | - Margaret Leinen
- Harbor Branch Oceanographic Institute, 5600 US Rt 1 North, Fort Pierce, FL 34946 USA
| | | | - Naomi E. Vaughan
- Tyndall Centre for Climate Change Research, School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ UK
| | - Anthony C. Janetos
- Joint Global Change Research Institute Pacific Northwest National Laboratory/University of Maryland, 5825 University Research Court, Suite 3500, College Park, MD 20740 USA
| | - Philip W. Boyd
- NIWA Centre of Chemical & Physical Oceanography, Department of Chemistry, University of Otago, Dunedin, New Zealand
| | - Richard J. Norby
- Environmental Sciences Division, Oak Ridge National Laboratory, Bethel Valley Road, Bldg. 2040, MS-6301, Oak Ridge, TN 37831-6301 USA
| | - Ken Caldeira
- Department of Global Ecology, Carnegie Institution, Stanford, CA 94305 USA
| | - Joonas Merikanto
- Division of Atmospheric Sciences, Department of Physics, University of Helsinki, P.O Box 64, 00014 Helsinki, Finland
| | - Paulo Artaxo
- Institute of Physics, University of São Paulo, Rua do Matão, Travessa R, 187, São Paulo, SP CEP 05508-090 Brazil
| | - Jerry Melillo
- The Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA 02543 USA
| | - M. Granger Morgan
- Department of Engineering and Public Policy, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 USA
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Johnson MT, Vaughan NE, Goodwin P, Goldblatt C, Roudesli S, Lenton TM. Why NH3is not a candidate reagent for ambient CO2fixation: A response to “Alternative solution to global warming arising from CO2emissions-Partial neutralization of tropospheric H2CO3with NH3”. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/ep.10298] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Abstract
Cognitive slowing that accompanies aging may be reflected in temporal aspects of auditory processing. The purpose of this study was to investigate the effects of age, type of test, and rate of speech on temporal auditory processing. Listeners were divided into three groups: young (25- to 35-year-olds), middle aged (45- to 55-year-olds), and older (65- to 75-year-olds). A method of time compression known as Synchronized Overlap Add (SOLA) was used to increase the rate of speech. This method provides a high-quality speech signal and limits the distortions that may confound the temporal effects on time-compressed tests of speech intelligibility. Listeners performed four speech understanding tasks: sentence repetition, sentence intelligibility rating, connected discourse intelligibility rating, and connected discourse comprehension question and answers at three time compression rates (60%, 70%, and 80%). Although the older group performed more poorly on all tests, only the connected discourse intelligibility rating test was sensitive to age differences among all three groups. This difference did not appear to increase with rate increases but was present only at the 70% compression rate. In addition, variability was especially high in the oldest group of participants.
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Affiliation(s)
- N E Vaughan
- Department of Speech and Hearing Sciences, Washington State University, Spokane, USA
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