2010 the hot one says British team

March 20, 2012
Global temeratures

An update of HadCRUT, the global temperature dataset compiled by the UK Met Office’s Hadley Centre and the University of East Anglia's Climatic Research Unit, has resulted in 2010 rather than 1988 being listed as the hottest year on record.

Compiled from temperature observations obtained over land and sea, HadCRUT is used as a basis for a global temperature record going back to 1850. The latest version of the dataset, called HadCRUT4, includes newly available data; notably adding much more information from the sparsely observed higher northern latitudes.

Differences in the way sea surface temperature observations have been collected have been taken account of and the new version also provides much more detail on uncertainty.

"The new study brings together our latest and most comprehensive databases of land and marine temperature observations, along with recent advances in our understanding of how measurements were made at sea,” said Colin Morice, climate monitoring research scientist at the Met Office. “These have been combined to give us a clearer picture of what the historical data can tell us about global climate change over the past 161 years.

"Updates have resulted in some changes to individual years in the nominal global mean temperature record, but have not changed the overall warming signal of about 0.75 °C since 1900."

One of the key reasons for slight changes to mean temperature for later years in HadCRUT4 is the inclusion of much more data from the Arctic, an area, which is warming faster than other parts of the world.

"HadCRUT is underpinned by observations and we've previously been clear it may not be fully capturing changes in the Arctic because we have had so little data from the area,” said Phil Jones, director of the Climatic Research Unit.

"For the latest version we have included observations from more than 400 stations across the Arctic, Russia and Canada. This has led to better representation of what's going on in the large geographical region."