There is a growing body of literature on economic aspects of global warming Whereas the research in greenhouse gas (GHG) abatement costs has provided many studies, the question of greenhouse damage valuation has gained little attention yet Ongoing the first section of this paper provides a brief overview of the main results relating to the costs of reducing CO2 emission. Afterwards the main interest is focused to the benefits of emission abatement, defined as the benefits from avoided damages. A synthesis of both costs and benefits is to find an economical\y efficient war for the optimum amongst emission abatement and not avoided damages otherwise. Guided by the mainly applied Cost-Benefit-Analysis (CBA), there are several examinations to evaluate the social costs of greenhouse gas emissions. Finally same criticism related to the here presented and often applied Cost-Benefit-Approach as well as an outlook will follow.