This report presents an account of the government assignment which the Swedish Environmental Protection Agency was given in the appropriation directions for 2003 to investigate suitable forms of continued international work on climate. The assignment has been carried out in co-operation with the Swedish Energy Agency.A maximum increase in temperature of 2ºC was the point of departure when the EU’s climate target was formulated in 1996. We have not found anything to suggest that this level might need to be revised. A global hedging strategy should be applied to deal with the uncertainties associated with the problem of climate change. The uncertainties relate to what concentrations occur, what temperatures they give rise to and what effects this in turn has. Risks of irreversible effects can be managed within a hedging strategy.