As part of the negotiations under the United Nations Framework Convention on Climate Change (UNFCCC) on the Kyoto Protocol, the delegation of Brazil made a proposal, in May 1997, to set differentiated emissions reduction targets for Parties according to the impact of their historic emissions on temperature rise (document FCCC/AGBM/1997/MISC.1/Add.3). The scientific and methodological aspects of the proposal were referred to the Subsidiary Body for Scientific and Technological Advice (SBSTA) for further consideration.

During SBSTA 17 (New Delhi, October/November 2002), the SBSTA agreed that work on the scientific and methodological aspects of the proposal by Brazil should be continued by the scientific community and that such work should be of a standard consistent with the practices of peer-reviewed published science. It invited the scientific community, including scientific and assessment programmes, such as the International Geosphere-Biosphere Programme, the World Climate Research Programme, the International Human Dimensions Programme on Global Environmental Change and the Intergovernmental Panel on Climate Change to provide information to Parties, and each other, on their interests in the work. (Document FCCC/SBSTA/2002/L.24, see Appendix A).

The governments of Brazil and the United Kingdom of Great Britain and Northern Ireland supported a third expert meeting on the Brazilian proposal held from 8 - 9 September 2003 in Berlin. The Government of Germany has also kindly offered the facilities.

At the meeting, the experts agreed to continue the work on the modelling and assessment of contributions to climate change (MATCH) to respond to the mandate of the SBSTA in a process up to 2005. The aim of this ad-hoc group is to improve the robustness of the preliminary results concerning contributions to climate change based on a proposal by Brazil for the calculation of contributions of GHG to climate change and to explore the uncertainty and sensitivity of the results to different assumptions.