Jun 28, 2009

Probabilistic estimates of recent changes in temperature: a multi-scale attribution analysis

Nikolaos Christidis, Peter A. Stott, Francis W. Zwiers, Hideo Shiogama, Toru Nozawa
Climate Dynamics
  • Investigates the role of anthropogenic forcings in temperature changes during recent decades over a range of spatial scales
  • Considers changes in the annual mean surface temperature and also in the warmest night of the year, which has implications for human health
  • Produces distributions of regional trends with and without the effect of human activity using constraints from a global optimal detection analysis
  • Estimates anthropogenic forcings to have more than doubled the likelihood of mean warming in all regions considered except central North America, where results are more model dependent
  • Finds the likelihood of warming of the warmest night has also increased, but the estimated change is more uncertain
  • Inferences on sub-continental scales are indicative rather than definitive because of the absence of locally important forcings and processes in model simulations, as well as model biases
  • Concludes that a multi-model approach is essential as model inconsistencies may impact regional analyses