Agence France-Presse: The risk posed to mankind and the environment by even small changes in average global temperatures is much higher than believed even a few years ago, a study said Monday. Published by the Proceedings of the National Academy of Sciences, the study updated a 2001 assessment by the Inter-governmental Panel on Climate Change that looked at temperature changes and the risks they pose. “Today, we have to assume that the risks of negative impacts of climate change on humans and nature …