Description

Global mean temperature increased by 0.4°C between 1992 and 2010

The average annual mean atmospheric temperature shows yearly variations, caused for example by tropical El Nin?o-La Nin?a cycles. Viewed over a longer time period, one can nevertheless observe a slow, but steady increase with occasional peaks. The annual mean temperature, as displayed, is calculated by three leading climate research centres, producing slightly different values — the general upward trend however is the same for all of them, with an increase of about 0.2°C per decade (Hansen and others 2006). “Most of the observed increase in global average temperature since the mid- 20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations” (IPCC 2007b). This map shows how much warmer temperatures during the decade 2000-2009 were compared to average temperatures recorded between 1951 and 1980 (a common reference period for climate studies). “The most extreme warming, shown in red, was in the Arctic. Very few areas saw cooler than average temperatures, shown in blue” (Voiland 2010). The last decade was the warmest on record since 1880; it was warmer than the previous record decade 1990-1999.

This graphic is part of the publication Keeping Track of Our Changing Environment.

Related items