The year 2010 is almost certain to rank among the three warmest years since the beginning of instrumental climate records in 1850, with the possibility of topping the chart, the United Nations World Meteorological Organization (WMO) reported today.
The global combined sea surface and land surface air temperature for January–October is estimated at 0.55 degrees Celsius, plus or minus 0.11 degrees, (0.99 degrees Fahrenheit, plus or minus 0.20 degrees) above the 1961–1990 annual average of 14 degrees Celsius (57.2 degrees Fahrenheit) – at present the highest on record, ahead 1998’s January-October increase of 0.53 degrees Celsius and that of 2005 at 0.52 degrees Celsius.
The final ranking of 2010 will not become clear until November and December data are analysed in early 2011. According to preliminary operational data from 1-25 November, global temperatures are similar to those of November 2005, indicating that global temperatures for 2010 continue to track near record levels.
The release of the data, compiled with input from WMO’s 189 member States, comes as officials from around the world meet in Cancún, Mexico, at a UN climate change conference in a bid to make further progress on curbing human-made pollution that scientists say has greatly increased global warming and climate change since the onset of the industrial age.
This year saw the third-lowest Arctic summer sea ice on record after 2007 and 2008, reached on 19 September with an area of 4.6 million square kilometres, more than 2 million square kilometres below the long-term average. The autumn 2010 freeze-up has also been abnormally slow, with the ice cover as of 28 November the lowest on record for this time of year.
In contrast, the extent of Antarctic sea ice was generally slightly above normal, with the lowest monthly average at 3.16 million square kilometres in February, 0.22 million square kilometres above the long-term average. Temperatures averaged over the Antarctic region were also slightly above normal.
Surface air temperatures over land were above normal across most parts of the world, with the most extreme occurring in two major regions – most of Canada and Greenland with mean annual temperatures 3 degrees Celsius or more above normal in parts of west Greenland and the eastern Canadian Arctic, and most of the northern half of Africa and southern Asia as far east as the western half of China with temperatures 1 to 3 degrees Celsius above normal.
Many parts of both regions had their warmest year on record, including large parts of northern Africa, the Arabian Peninsula, Turkey and Tunisia, as well as much of the Canadian Arctic and coastal Greenland. Temperatures averaged over Canada have also been the highest on record.
Only limited land areas had below-normal temperatures, most notably parts of western and central Siberia in Russia, parts of southern South America, interior Australia, parts of northern and western Europe, eastern China and the southeast United States. It was the coolest year since 1996 for northern Europe, and since 1998 for northern Asia, due mainly to below-normal temperatures during the winter.
A number of northern European countries are also likely to have their coolest year since 1996, including the United Kingdom, Germany, France and Norway.
Sea surface temperatures were below normal over most of the eastern half of the Pacific Ocean as a result of the La Niña event which developed during the year, but were well above normal over most parts of the Indian and Atlantic Oceans. The tropical North Atlantic was especially warm with temperatures at record levels over most of the area east of longitude 55 degrees west.
In a survey of various regions, the WMO noted that 2010 saw the worst flooding in Pakistan in its history from exceptionally heavy monsoon rains, in which more than 1,500 lives were lost and over 20 million people were displaced. Summer rainfall was also well above normal in western India, and China experienced its most significant monsoon flooding since 1998.
But monsoon average rainfall over India was only 2 per cent above normal, and well below normal in north-eastern India and Bangladesh, which had its driest monsoon season since 1994.
The Northern Hemisphere summer saw exceptional heat waves in several parts of Eurasia, with the most extreme centred over western Russia. Neighbouring countries were also affected, with extreme high maximum temperatures recorded in Finland, Ukraine and Belarus, and record high numbers of extreme warm nights in parts of south-eastern Europe, including Serbia.
The winter was abnormal in many parts of the Northern Hemisphere, with Ireland and Scotland experiencing their coldest winter since 1962-63. Many other parts of northern and central Europe had their coldest winter since 1978-79, 1986-87 or 1995-96, although the temperatures were generally not exceptional in a long-term historical context.
Northern Africa recorded warm conditions during winter, while Canada had its warmest and driest winter on record, with national temperatures 4 degrees Celsius above the long-term average.
Parts of the Amazon basin were badly affected by drought during the later part of 2010, while parts of south-western China experienced severe drought through late 2009 and early 2010.