2010 ties record for world's warmest year: World Meteorological Organization

In 2010, global average temperature was 0.53°C (0.95°F) above the 1961-90 mean. This value is 0.01°C (0.02°F) above the nominal temperature in 2005, and 0.02°C (0.05°F) above 1998. The difference between the three years is less than the margin of uncertainty (± 0.09°C or ± 0.16°F) in comparing the data.

These statistics are based on data sets maintained by the UK Meteorological Office Hadley Centre/Climatic Research Unit (HadCRU), the U.S. National Climatic Data Center (NCDC), and the U.S. National Aeronautics and Space Administration (NASA).

Arctic sea-ice cover in December 2010 was the lowest on record, with an average monthly extent of 12 million square kilometres, 1.35 million square kilometres below the 1979-2000 average for December. This follows the third-lowest minimum ice extent recorded in September.

"The 2010 data confirm the Earth's significant long-term warming trend," said WMO Secretary-General Michel Jarraud. "The ten warmest years on record have all occurred since 1998."

Over the ten years from 2001 to 2010, global temperatures have averaged 0.46°C (0.83°F) above the 1961-1990 average, and are the highest ever recorded for a 10-year period since the beginning of instrumental climate records. Recent warming has been especially strong in Africa, parts of Asia, and parts of the Arctic, with many subregions registering temperatures 1.2 to 1.4°C (2.2 to 2.5°F) above the long-term average.

2010 was an exceptionally warm year over much of Africa and southern and western Asia, and in Greenland and Arctic Canada, with many parts of these regions having their hottest years on record.

Over land few parts of the world were significantly cooler than average in 2010, the most notable being parts of northern Europe and central and eastern Australia.

December 2010 was exceptionally warm in eastern Canada and Greenland. It was abnormally cold through large parts of northern and western Europe, with monthly mean temperatures as much as 10°C below normal at some locations in Norway and Sweden. Many places in Scandinavia had their coldest December on record. December in Central England was the coldest since 1890. Heavy snowfalls severely disrupted transport in many parts of Europe. It was also colder than average in large parts of the Russian Federation and in the eastern United States, where snow also severely disrupted transport.

Recent significant weather and climate events

The year 2010 was characterized by a high number of extreme weather events, including the heatwave in Russia and the devastating monsoonal floods in Pakistan. These were described in WMO's provisional statement on the status of the global climate issued December 2010 (http://www.wmo.int/pages/mediacentre/press_releases/pr_904_en.html)

There have been many major weather and climate events in late 2010 and early 2011. These include:

• In early January floods affected more than 800 000 people in Sri Lanka according to the UN Office for the Coordination of Humanitarian Affairs. The Philippines were also severely affected by floods and mudslides during January.
• Flash floods in the mountain areas near the city of Rio de Janeiro in Brazil in the second week of January resulted in more than 700 deaths, many of them in mudslides. This is one of the highest death tolls due to a single natural disaster in Brazilian history.
• Severe flooding occurred in eastern Australia in December and the first half of January, associated with the continuing strong La Niña event. The most extensive damage was in the city of Brisbane, which had its second-highest flood of the last 100 years after that of January 1974. In financial terms it is expected to be the most costly natural disaster in Australia's history. Previous strong La Niña events have also been associated with severe and widespread flooding in eastern Australia, notably in 1974 and 1955.

Background

The information for 2010 is based on climate data from networks of land-based weather and climate stations, ships and buoys, as well as satellites. The data are continuously collected and disseminated by the National Meteorological and Hydrological Services (NMHSs) of the 189 Members of WMO and several collaborating research institutions. The data continuously feed three main depository global climate data and analysis centres, which develop and maintain homogeneous global climate datasets based on peer-reviewed methodologies. The WMO global temperature analysis is thus principally based on three complementary datasets. One is the combined dataset maintained by both the Hadley Centre of the UK Met Office and the Climatic Research Unit, University of East Anglia, United Kingdom. Another dataset is maintained by the National Oceanic and Atmospheric Administration (NOAA) under the United States Department of Commerce, and the third one is from the Goddard Institute of Space Studies (GISS) operated by the National Aeronautics and Space Administration (NASA).

The updated data complements the Provisional Statement on the Status of the Global Climate 2010 published by WMO on 3 Dec. 2010 (http://www.wmo.int/pages/mediacentre/press_releases/pr_904_en.html).

The final Statement will be published in March 2011.