May 15, 2008

Attributing physical and biological impacts to anthropogenic climate change

by
Rosenzweig, C., D. Karoly, M. Vicarelli, P. Neofotis, Q. Wu, G. Casassa, A. Menzel, T.L. Root, N. Estrella, B. Seguin, P. Tryjanowski, C. Liu, S. Rawlins, and A. Imeson
,
Nature
  • 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
  • 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 anthropogenic climate change is having a significant impact on physical and biological systems globally and in some continents—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
  • Finds that most (about 90% of the > 29,500 data series, P = 0.001) changes in these systems at the global scale have been in the direction expected as a response to warming
  • Finds that 95% per cent of the 829 documented physical changes have been in directions consistent with warming, such as glacier wastage and an earlier spring peak of river discharge