Geoengineering, encompassing a broad set of methods and technologies, has been an increasing focus of scientific research, and the scientific basis of geoengineering options, risks, and impacts will be assessed across the three contributions to the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC). In preparation of this task, Working Groups I, II, and III (WGI, WGII, and WGIII) of the IPCC held a joint Expert Meeting on Geoengineering in Lima, Peru, from 20 to 22 June 2011. The Expert Meeting provided a valuable opportunity for experts from a wide range of disciplines and across WGI, WGII, and WGIII to discuss terminology, to clarify concepts and definitions, and to consider emerging issues. Overall the meeting enabled a better understanding and coordination across the three IPCC Working Groups in the context of AR5 assessment efforts underway.
This meeting report summarizes discussions of the Expert Meeting. At its core is a summary of the synthesis session and main outcomes of the meeting. It also contains summaries of meeting discussions of geoengineering approaches and crosscutting issues, as well as extended abstracts for the meeting’s keynote and poster presentations.