Implications of Proposed CO2 Emissions Limitations 

This Technical Paper was produced at the request of the Subsidiary Body for Scientific and Technological Advice (SBSTA) of the Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change (UN/FCCC). At its second session (Geneva, 27 February–4 March 1996) SBSTA requested IPCC to provide an assessment of the implications for projected temperature increases, sea  evel rise and other changes in climate§1 of different proposals for the limitation of greenhouse gas emissions2 by Annex I Parties3§. The IPCC Bureau approved the production of a Technical Paper in order to meet this request at its tenth session (Geneva, 28–29 March 1996).

An initial problem with the preparation of a useful Technical Paper on this subject was that none of the emissions limitation proposals tabled at that time extended beyond the year 2010. For carbon dioxide (CO2), even with large emissions differences in 2010, differences in CO2 concentration, global mean temperature and global mean sea level in 2010 wil be comparatively small because of the slow responses of atmospheric CO2 and the climate and sea level systems to emissions changes. The consequences of greenhouse gas emissions changes, and CO2 emissions changes in particular, take decades to centuries to manifest themselves fully in the climate system. Thus, in order to carry out useful climate and sea level calculations it is necessary to have information that extends beyond just a few decades. A set of extended emissions limitation scenarios§ were therefore required to enable the analysis to be carried out. It was decided during the twelfth session of the IPCC (Mexico City, 11–13 September 1996) that, to generate information beyond 2010, further guidance was required from SBSTA.