As part of the negotiations on the Kyoto Protocol, the delegation of Brazil made a proposal, in May 1997, to set differentiated emission reduction targets for Parties according to the impact of their historic emissions on temperature rise (see document FCCC/AGBM/1997/MISC.1/Add.3).

The proposal by Brazil is based on the assumption that emissions in a particular year, 1990 for example, do not reflect the true contribution of a country to global climate change, which is related to cumulative emissions of greenhouse gases. The historic responsibility of all countries is calculated through the use of a simple equation that relates temperature increase to the accumulation of greenhouse gases in the atmosphere. A global climate change mitigation goal can thus be established in terms of temperature increase, and this can then be translated into emission targets for individual countries.

The proposal also advocated the establishment of a clean development fund, but that part was overtaken by the clean development mechanism defined in Article 12 of the Kyoto Protocol.
COP 3 referred the proposal to the SBSTA for advice on the methodological and scientific issues that it raised.

At SBSTA 13 in Lyon the secretariat distributed a letter to Parties seeking guidance and advice from parties regarding nominations to the UNFCCCC roster of experts