Risk benefits of climate-friendly energy supply options

One of the central goals of sustainable development is the reduction of Greenhouse Gas (GHG) emissions. This is needed in order to prevent the anticipated climate change, and the potentially serious consequences for human beings and the environment. Energy supply systems constitute the dominant contributors to GHG emissions. This paper examines three illustrative emission scenarios for world-wide energy supply in the 21st Century. These scenarios, including the associated GHG and major pollutant emissions, were chosen from a set established by the Intergovernmental Panel on Climate Change (IPCC). Using the emissions as a starting point, and based on recent findings concerning the impact on the environment and the financial costs resulting from global climate change on the one hand, and regional air pollution on the other hand, the present work provides estimates of the scenario-dependent, world-wide cumulative damage. The fossil-intensive reference scenario leads to overall damages which correspond to very substantial losses in Gross Domestic Product (GDP), and which widely exceed the damages caused by the scenarios reflecting climate-friendly policies. Generally, the somewhat speculative estimates of the GHG-specific damages are much less significant than damages to human health and the environment caused by the major air pollutants. This means that the secondary benefits of climate-friendly, energy-supply options, i.e. those which avoid the impacts due to air pollution, alone justify strategies protecting the climate. (author)