May 15, 2008

Attributing physical and biological impacts to anthropogenic climate change

Cynthia Rosenzweig, David Karoly, Marta Vicarelli, Peter Neofotis, Qigang Wu, Gino Casassa, Annette Menzel, Terry L. Root, Nicole Estrella, Bernard Seguin, Piotr Tryjanowski, Chunzhen Liu, Samuel Rawlins, Anton Imeson
  • States that significant changes in physical and biological systems are occurring on all continents and in most oceans, with a concentration of available data in Europe and North America
  • States that most of these changes are in the direction expected with warming temperature
  • Shows that these changes in natural systems since at least 1970 are occurring in regions of observed temperature increases, and that these temperature increases at continental scales cannot be explained by natural climate variations alone
  • Concludes that — given the conclusions from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report that most of the observed increase in global average temperatures since the mid-twentieth century is very likely to be due to the observed increase in anthropogenic greenhouse gas concentrations, and furthermore that it is likely that there has been significant anthropogenic warming over the past 50 years averaged over each continent except Antarctica — anthropogenic climate change is having a significant impact on physical and biological systems globally and in some continents