1. Royal Society working group Geoengineering the Climate: Science, Governance and Uncertainty (Royal Society, 2009) available at
http://go.nature.com/zxpwun
2. Rayner, S., Redgwell, C., Savulescu, J., Pidgeon, N. & Kruger, T. Memorandum on Draft Principles for the Conduct of Geoengineering Research (House of Commons Science and Technology Committee Enquiry into The Regulation of Geoengineering; 2009).
3. http://www.handsoffmotherearth.org/hose-experiment/spice-opposition-letter/
4. Nurse, P. Letter to The Guardian 8 September 2011 available at
http://go.nature.com/efnybg