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
This is the start : We are failing today to stay below 2C ...
This is from 2009! What has changed since then?
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
- 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
- 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
- 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
- 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