This paper presents the dimensions of the climate change problem and its economic effects as well as the evolution of the international meetings to cope with it. In these lines it discusses the use of Integrated Assessment Models (IAMs), the damage cost estimates and various other issues related to global warming and concerning the significance of uncertainty and risk aversion, the importance of discounting and the impact of financial crisis on emissions predictions. The methods of constructing abatement cost curves together with adaptation policies are presented. . I It t a al ls so o r re ef fe er rs s t to o the basic policy approaches for reducing greenhouse gases paying attention to emissions trading schemes