How soon will climate records of the 20th century be broken according to climate model simulations?

Abstract

What will happen to local record values of temperature and precipitation in a world with ongoing global warming?Here we first examine how many of the observed local temperature maxima of 1901-2006 occurred in the years 2001-2006 and compare the observations with model simulations. Then we study whether, and how soon, the models simulate the climate records of the 20th century to be broken in the ongoing 21st century. In 27% of our analysis area, the highest annual mean temperatures of the whole period 1901-2006 were observed in 2001-2006. For the 22 climate models in our study, this fraction varies from 17% to 70%, with a multimodel mean of 40%. In simulations based on the SRES A1B emissions scenario, the highest annual mean temperature of the 20th century is exceeded on average in 99% of the global area by the year 2080. The same number for the highest (lowest) annual precipitation total is 60% (43%). Monthly and seasonal temperature and precipitation records are also analysed, and the geographical distributions of record value occurrence are related to the distributions of time mean climate change and magnitude of interannual variability. © 2009 The Authors Journal compilation © 2009 Blackwell Munksgaard.