ABSTRACT
The Intergovernmental Panel on Climate Change (IPCC) has some agenda-setting power for global climate policy. This explains worries about the fact that the governments had decided in 2009 that the IPCC's Fifth Assessment Report (AR5) was to explicitly address geoengineering options, which could then possibly legitimate the serious consideration of such options in global climate policy negotiations. Such worries, however, neglect two factors. First, the IPCC has a long history of dealing with geoengineering and, second, the IPCC performs its assessments without endorsing any options and being based on what is available in the primary literature. It must be admitted that the assessment of geoengineering options in the AR5 of 2014 has been the most extensive of all IPCC reports, mainly because much literature has appeared in the AR5. This is a moral issue: the IPCC carries a special responsibility to give the most comprehensive and clear portrayal of uncertainties, risk, and limitations of geoengineering methods and technologies.
