Page "IPCC Third Assessment Report" Paragraph 24

The TAR projects impacts according to possible future changes in global mean temperature.

Other projections are based on scenarios that the IPCC has developed.

In 2000, the IPCC published 40 different scenarios ( the " SRES " scenarios ) which contain estimates of future changes in anthropogenic emissions of greenhouse gases and aerosols.

The SRES scenarios project a wide range of possible changes in future social and economic development, and projected climate change impacts vary according to the scenario considered.

The IPCC has not assigned probabilities to the 40 SRES scenarios.

Some authors have argued that some SRES scenarios are more likely to occur than others.