Royal Society - David Keith

8 Annexes
8.1 Evaluation criteria
Prior to any large scale experimentation or deployment it is
recommended that geoengineering methods be evaluated
based on the following criteria:
1) Legality:
• Need for prior authorisation under national or
international law or policy;
• Likelihood of environmental impacts that would
contravene national or international laws.
2) Effectiveness:
• Strength of scientific basis of method;
• State of development of the technology;
• Whether demonstrated to be technically feasible;
• Potential magnitude of effect;
• Spatial scale of influence on the climate system
and uniformity of the effect;
• Scaleability of the intervention (from small to large).
3) Timeliness:
• Timescale to be ready for implementation;
• Time taken to affect the climate system and
duration of effect;
• Time required for the climate system to stop
responding if the method is stopped.
4) Impacts:
• State of understanding of intended effects on the
climate system?
• Verifiability of intended effects;
• Potential for the method and its effects be stopped
once deployed;
• Likely effects on the climate system of turning the
method off;
• Foreseeable environmental impacts (nature, spatial
scale and magnitude);
• Potential for mitigation of environmental impacts;
• Potential for human health impacts;
• Potential for predictable, but unintended
consequences, and scope for management of these;
• Potential liability issues from adverse
environmental, economic or social impacts.
5) Costs: to be based so far as possible on full life cycle
assessment, including:
• The direct financial costs of any R&D required;
• For deployment: the direct financial costs of set up,
implementation and ongoing operational costs;
• Magnitude of expected net carbon accounting
benefit, where applicable.
6) Funding support:
• Availability of funding for R&D;
• Mechanism for funding of deployment and long
term operation;
• Costs of development and implementation
compared to those of conventional mitigation.
7) Public acceptability:
• How novel is the method, (have similar
technologies already been successfully applied)?
• Who is proposing to do the R&D or deployment?
Do they have vested interests? What benefits are
they likely to gain?
• Does the method involve releasing material into the
environment?
• Are the activities localised, or widely dispersed?
• Will activities be controlled locally, or centrally?
• Can the activity, and its effects be contained?
8) Reversibility; what are the technical, political,
social and economic implications of ceasing the
activity?
The Royal Society
Geoengineering the Climate I September 2009 I 69