Joseph Alcamo is Chief Scientist of the United Nations Environment Programme where he is responsible for engaging the scientific community in the policy arena to help solve global environmental problems. He is on leave as Professor of Environmental Science and Engineering and Director of the Center of Environmental Systems Research at the University of Kassel, Germany. He was a coordinating lead author of the assessment of climate impacts in Europe in the Fourth Assessment report of the IPCC. Jorgen E. Olesen is Professor of agriculture and climate change at Aarhus University in Denmark. He was a lead author in the Fourth Assessment report of the Intergovernmental Panel on Climate Change. He was a member of the Commission on Climate Change Policy for the Government in Denmark. He is a member of the Danish Council on Ethics, and he chairs the food and agriculture group of the Danish green think tank CONCITO.