Report from Royal Society (2009)

What?

Geoengineering the climate: science, governance and uncertainty

Summary

Notes

6 Conclusions and recommendations

• The assessments are preliminary because of lack of research. General assessment is still valid.

6.1

• Geoengineering is likely to be
• tech feasible
• could substantially reduce costs of climate change
• could substantially reduce risk of climate change
• Major uncertainties
• Not mid term
• Should not divert from emissions reduction

• We are failing in reductions today = we might need geoengineering as a complement

• We need
• International coordination of research on the most promising methods
• International cooperation to assess feasibility, risks, benefits ... and governance
• Public dialog and aligned governance on research, development, deployement

6.2

• We should compare how good each method is at reducing temperature ... not easy since the Techs are very different
• CDR vs SRM:
• Timescale
• effect on non temperature impacts of climate change
• risk levels

6.3

• No tech can substitute for reducing emissions
• No clear winner today + depends on what we want to achieve
• CDR
• Lower risk
• Addresses the source (not just temperature)
• Longer time scale
• Impact on local environments / trade offs
• CDR methods are classified in order of potential
• SRM
• Termination problem: it needs to be maintained over centuries
• Do not address ocean acidification
• Introduces local variations in precipitations, wind, biodiversity ... / not a copy of our current climate
• Might work in case of emergency
• SRM methods are classified in order of potential
• Stratospheric aerosol methods
• most potential: large scale impact thanks to uniform distribution of effect
• High risk
• Cloud brightening methods
• Localized temperature reduction
• Easier to test and less governance problems
• Space based
• More uniform
• Might work best if long term is needed
• Not feasible today
• Exit strategy might be easier

6.4

• Need to assess these technologies and costs based on best available science
• Legality
• Effectiveness
• Timeliness of implementation and effect
• Eviro, social and economic impacts + unintended consequences
• Costs (direct and indirect)
• Funding
• Public acceptability
• Reversibility

6.5

• This will have a critical impact on develop of these methods
• Need to work on
• Transparency
• independence of commercial interests in evaluating the options
• proper evaluation of impacts
• Public attitude dominated by risks of things going wrong
• Generally negative
• depend on the method

6.6

• Governance issues are substantial and serious
• There will be winners and losers
• Today: no treaties or institutions can regulate the range of activities ... fear that a lone state / company / individual could do geoengineering on his own

6.7

• Research is urgently needed to evaluate feasibility and risks
• Small scale field experiements
• Modelling
• Enviro and social impact
• Costs
• Removing other gases than CO2?
• Progress can be made cheaply: a few % of R&D of new energy development