CLIMATE INTERVENTION
Marcia McNu) (Chair), Waleed Abdala3, Sco) Doney, David Titley BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
CLIMATE IS CHANGING
Observed Change in Surface Temperature •  The signs of changing climate are all around us: IPCC, 2013 –  Greenhouse gases are increasing –  Sea level is rising –  Ice sheets and glaciers are mel3ng –  Global temperatures are increasing •  Climate change impacts people, ecosystems, and the economy BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
2 POSSIBLE CLIMATE RESPONSE OPTIONS
•  Reducing greenhouse gas emissions –  “Mi3ga3on” •  Adap3ng to the impacts of climate change –  “Adapta3on” •  Climate Interven3on??? BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
3 COMMITTEE ON GEOENGINEERING CLIMATE:
TECHNICAL EVALUATION AND DISCUSSION OF IMPACTS
DOE, NASA, NOAA, U.S. intelligence community, and Na3onal Academy of Sciences supported this study Technical assessment of two classes of climate interven3on technologies –  Removing carbon dioxide from the atmosphere –  Reducing sunlight absorbed by Earth in order to cool planet’s surface •  What is currently known –  Science -­‐ risks and consequences –  Viability for implementa3on •  Iden3fy future research needed •  Comment generally on poten3al societal, legal, and ethical considera3ons BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
4 COMMITTEE ON GEOENGINEERING CLIMATE:
TECHNICAL EVALUATION AND DISCUSSION OF IMPACTS
Marcia K. McNu3 (Chair) Science / AAAS Waleed Abdala; University of Colorado, Boulder Ken Caldeira Carnegie Ins3tu3on for Science Sco3 C. Doney Woods Hole Oceanographic Ins3tu3on Paul G. Falkowski Rutgers, The State University of New Jersey Steve Fe3er University of Maryland James R. Fleming Colby College Steven P. Hamburg Environmental Defense Fund •
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M. Granger Morgan Carnegie Mellon University Joyce E. Penner University of Michigan Raymond T. Pierrehumbert University of Chicago Philip J. Rasch Pacific Northwest Na3onal Laboratory Lynn M. Russell Scripps Ins3tu3on of Oceanography John T. Snow University of Oklahoma David W. Titley Penn State University Jennifer Wilcox Stanford University The Commi)ee held four mee3ngs and interacted with dozens of scien3sts Reports were reviewed by 16 outside experts BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
5 THERE IS NO SUBSTITUTE
FOR MITIGATION AND ADAPTATION
Recommenda;on 1: Efforts to address climate change should con;nue to focus most heavily on •  mi;ga;ng greenhouse gas emissions •  in combina;on with adap;ng to the impacts of climate change because these approaches •  do not present poorly defined and poorly quan;fied risks and •  are at a greater state of technological readiness BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
6 CARBON DIOXIDE REMOVAL AND
RELIABLE SEQUESTRATION
Enhancing natural carbon sinks •  Changes in land use management –  Reforesta3on / afforesta3on –  Agricultural prac3ces •  Accelerated weathering –  Chemical reac3ons to form carbonate or silicate minerals •  Ocean iron fer3liza3on –  Adding iron to the ocean to boost the growth of phytoplankton BOARD ON ATMOSPHERIC
SCIENCES
AND CLIMATE
7 CARBON DIOXIDE REMOVAL AND
RELIABLE SEQUESTRATION
Other technologies •  Direct Air Capture and Sequestra3on (DACS) –  Chemical scrubbing processes •  Bioenergy with Carbon Capture and Sequestra3on (BECCS) –  Use plants (biomass) to produce energy –  Capture carbon dioxide from power plant and sequester underground BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
8 CARBON DIOXIDE REMOVAL READY FOR
INCREASED RESEARCH AND DEVELOPMENT
Recommenda;on 2: The Commi3ee recommends research and development investment to •  improve methods of carbon dioxide removal and disposal at scales that ma3er in par;cular to •  minimize energy and materials consump;on •  iden;fy and quan;fy risks •  lower costs, and •  develop reliable sequestra;on and monitoring BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
9 ALBEDO MODIFICATION
Albedo modifica3on could reduce amount of sunlight absorbed by Earth in order to cool planet’s surface quickly •  The report considered two strategies: –  Stratospheric aerosols –  Marine cloud brightening Elsewhere referred to as “Solar Radia9on Management” BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
10 “Albedo” is the propor9on of incoming sunlight that is reflected back to space ALBEDO MODIFICATION POSES
SIGNIFICANT RISKS
Environmental risks – both known and poorly known –  Decreases in stratospheric ozone –  Changes in the amount and pa)erns of precipita3on –  No reduc3on of root cause of climate change (greenhouse gases) –  Poorly understood regional variability –  Poten3al risk of millennial dependence Significant poten3al for unan3cipated, unmanageable, and regre)able consequences –  Including poli3cal, social, legal, economic, and ethical dimensions Recommenda;on 3: Albedo modifica;on at scales sufficient to alter climate should not be deployed at this ;me BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
11 ALBEDO MODIFICATION RESEARCH
Research needed to determine if albedo modifica3on could be viable climate response –  If there were a climate emergency –  Could it be key part of a porjolio of responses? Be)er understanding of consequences needed if there were an ac3on by a unilateral / uncoordinated actor Recommenda;on 4: The Commi3ee recommends an albedo modifica;on research program be developed and implemented that emphasizes mul;ple benefit research that furthers •  basic understanding of the climate system •  and its human dimensions BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
12 ALBEDO MODIFICATION RESEARCH
Current observa3onal capabili3es lack sufficient capacity to detect and monitor environmental effects of albedo modifica3on deployment Recommenda;on 5: The Commi3ee recommends that the United States improve its capacity to detect and measure changes in radia;ve forcing and associated changes in climate BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
13 GOVERNANCE CONSIDERATIONS
More than just science involved in decisions on research and deployment •  Governance •  Ethical & legal considera3ons Albedo modifica3on research is not specifically addressed by any federal laws or regula3ons Need for transparent and inclusive conversa3ons Goal of governance should be to maximize benefits of research while minimizing risks BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
14 GOVERNANCE CONSIDERATIONS
Recommenda;on 6: The Commi3ee recommends the ini;a;on of a serious delibera;ve process to examine: (a)  what types of research governance, beyond those that already exist, may be needed for albedo modifica;on research, and (b)  the types of research that would require such governance, poten;ally based on the magnitude of their expected impact on radia;ve forcing, their poten;al for detrimental direct and indirect effects, and other considera;ons BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
15 CONCLUSIONS
•  The challenges of climate change require a porjolio of ac3ons with varying degrees of risk and efficacy •  There is no subs3tute for mi3ga3on and adapta3on •  Carbon dioxide removal strategies offer poten3al to decrease carbon dioxide concentra3ons in the atmosphere •  Albedo modifica3on strategies currently limited by unfamiliar and unquan3fiable risks and governance issues •  Any interven3on in Earth’s climate should be informed by a far more substan3ve body of scien3fic research than is available at present BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
16 ACKNOWLEDGMENTS
Sponsors Commi)ee Reviewers NRC Staff Numerous colleagues consulted during study Please visit americasclimatechoices.org to find: •
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Complete reports available for free PDF download Report in Brief (4-­‐page lay summary) Press release Informa3on about upcoming events, such as webinar Feb 26 Briefing slides and archived public release webcast Join the conversa3on : #ClimateInterven3on BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
Carbon Dioxide Removal proposals…
Albedo Modifica;on proposals…
… address the cause of human-­‐induced climate change (high atmospheric GHG concentra;ons).
…do not introduce novel global risks.
…do not address cause of human-­‐induced climate change (high atmospheric GHG concentra3ons).
… introduce novel global risks.
…are currently expensive (or comparable to the cost of emission reduc;on).
…are inexpensive to deploy (rela3ve to cost of emissions reduc3on).
…may produce only modest climate effects within decades.
…can produce substan3al climate effects within years.
…raise fewer and less difficult issues with respect to global governance.
…raise difficult issues with respect to global governance.
…will be judged largely on ques;ons related to …will be judged largely on ques3ons related to cost.
risk.
…may be implemented incrementally with limited effects as society becomes more serious about reducing GHG concentra;ons or slowing their growth.
…could be implemented suddenly, with large-­‐
scale impacts before enough research is available to understand their risks rela3ve to inac3on.
…require coopera;on by major carbon emi3ers to have a significant effect.
…could be done unilaterally.
…for likely future emissions scenarios, abrupt …for likely future emissions scenarios, abrupt termina3on would produce significant termina;on would have limited consequences consequences
americasclimatechoices.org BOARD ON ATMOSPHERIC
SCIENCES AND CLIMATE
18 #ClimateInterven;on