2010 equal warmest year on record globally, say NASA and NOAA

2010 Global surface temperatures matched 2005 as the equal warmest year on record according to NASA and the National Oceanic and Atmospheric Administration (NOAA). Global precipitation was also the wettest on record since 1900 according to NOAA.

Several oraganisations track global average temperatures using slightly different methodologies including the UK Met office, NASA, NOAA and the Japan Meteorological Organisation (JMO). In late December the JMO released it's data on global average surface temperatures finding that 2010 was the second hottest year on record behind 1998.


"If the warming trend continues, as is expected, if greenhouse gases continue to increase, the 2010 record will not stand for long," said James Hansen, the director of the Goddard Institute of Space Studies (GISS) - a part of NASA.

It was a record breaking year for global average temperature despite two strong moderating influences. "Certainly, it is interesting that 2010 was so warm despite the presence of a La Niña and a remarkably inactive sun, two factors that have a cooling influence on the planet, but far more important than any particular year's ranking are the decadal trends," Hansen said.

During the year a moderately strong El Niño transitioned to one of the strongest La Niña's on record. The El Niño Southern Oscillation (ENSO) is a weather pattern that has a global impact on temperatures and precipitation. It arises from changes in tropical sea surface temperatures (SST) and the air pressure of the overlying atmosphere in the Pacific ocean which changes trade wind patterns and monsoons and can devestate whole regions through drought or flooding rains as recently experienced in Queensland and the Philippines. La Nina is associated with below average sea surface temperatures in the mid Pacific and hence moderated down the global average surface temperature.

It is likely that with the next El Niño event the world could again see another global average surface temperature record smashed.

"Global temperature is rising as fast in the past decade as in the prior two decades, despite year-to-year fluctuations associated with the El Niño-La Niña cycle of tropical ocean temperature," Hansen and colleagues reported in the Dec. 14, 2010, issue of Reviews of Geophysics.

For a second year in a row there was strongly negative Arctic Oscillation which brought snowstorms and freezing weather to the mid-latitudes of North America, the UK and Europe.

While cold air has chilled the mid-latitudes, the Arctic has been warming at an unprecedented rate with northern Canada and Greenland suffering a winter heatwave with temperatures several degrees above average.

The GISS statement said that the unusual cold in the past two winters has caused scientists to begin to speculate about a potential connection to sea ice changes. "One possibility is that the heat source due to open water in Hudson Bay affected Arctic wind patterns, with a seesaw pattern that has Arctic air downstream pouring into Europe," Hansen said.

Comparison of Warmest Years between JMO and NOAA

Rank	JMO Year	JMO Anomaly °C	NOAA Year	NOAA Anomaly °C
1.	1998	+0.37C	2010	+0.62C
2.	2010	+0.36C	2005	+o.62C
3.	2005	+0.32C	1998	+0.60C
4.	2009	+0.31C	2003	+0.58C
5.	2006	+0.31C	2002	+0.58C
6.	2003	+0.31C	2009	+0.56C
7.	2002	+0.31C	2006	+0.56C
8.	2007	+0.28C	2007	+0.55C
9.	2004	+0.27C	2004	+0.54C
10.	2001	+0.27C	2001	+0.52C

NOAA - Global Climate Highlights for 2010

NOAA issued the following global climate highlights for 2010:

• Combined global land and ocean annual surface temperatures for 2010 tied with 2005 as the warmest such period on record at 1.12 F (0.62 C) above the 20th century average. The range of confidence (to the 95 percent level) associated with the combined surface temperature is +/- 0.13 F (+/- 0.07 C).*
  
• The global land surface temperatures for 2010 were tied for the second warmest on record at 1.73 F (0.96 C) above the 20th century average. The range of confidence associated with the land surface temperature is +/- 0.20 F (+/- 0.11 C).
  
• Global ocean surface temperatures for 2010 tied with 2005 as the third warmest on record, at 0.88 F (0.49 C) above the 20th century average. The range of confidence associated with the ocean surface temperature is +/- 0.11 F (+/- 0.06 C).
  
• In 2010 there was a dramatic shift in the El Niño-Southern Oscillation (ENSO), which influences global temperature and precipitation patterns — when a moderate-to-strong El Niño transitioned to La Niña conditions by July. At the end of November, La Niña was moderate-to-strong.
  
• According to the Global Historical Climatology Network, 2010 was the wettest year on record, in terms of global average precipitation. As with any year, precipitation patterns were highly variable from region to region.
  
• The 2010 Pacific hurricane season had seven named storms and three hurricanes, the fewest on record since the mid-1960s when scientists started using satellite observations. By contrast, the Atlantic season was extremely active, with 19 named storms and 12 hurricanes. The year tied for third- and second-most storms and hurricanes on record, respectively.
  
• The Arctic sea ice extent had a record long growing season, with the annual maximum occurring at the latest date, March 31, since records began in 1979. Despite the shorter-than-normal melting season, the Arctic still reached its third smallest annual sea ice minimum on record behind 2007 and 2008. The Antarctic sea ice extent reached its eighth smallest annual maximum extent in March, while in September, the Antarctic sea ice rapidly expanded to its third largest extent on record.
  
• A negative Arctic Oscillation (AO) in January and February helped usher in very cold Arctic air to much of the Northern Hemisphere. Record cold and major snowstorms with heavy accumulations occurred across much of eastern North America, Europe and Asia. The February AO index reached -4.266, the largest negative anomaly since records began in 1950.
  
• From mid-June to mid-August, an unusually strong jet stream shifted northward of western Russia while plunging southward into Pakistan. The jet stream remained locked in place for weeks, bringing an unprecedented two-month heat wave to Russia and contributing to devastating floods in Pakistan at the end of July.
  

Comparing the hemispheres, the 2010 Northern Hemisphere combined global land and ocean surface temperature was the warmest year on record, at 0.73°C (1.31°F) above the 20th century average. The 2010 Southern Hemisphere combined global land and ocean surface temperature was the sixth warmest year on record, at 0.51°C (0.92°F) above the 20th century average.

The global ocean surface temperature for 2010 tied with 2005 as the third warmest on record, at 0.49°C (0.88°F) above the 20th century average.

Australia

For Australia it was the warmest summer (2009/2010) on record, with average temperatures 0.2°C (0.4°F) higher than the previous record set during the summer of 1997/98.

NOAA cites the Australian Bureau of Meteorology for this summary:

"La Niña influenced the precipitation patterns over Australia during the latter part of the year. Heavy rainfall across the country brought cooler temperatures, leading to the country's fourth coolest spring (September–November; Northern Hemisphere fall) on record. Nationally averaged maximum temperatures were 1.23°C (2.21°F) below normal, the lowest since 1999. December brought even cooler anomalies to the country. The average temperature for the month was 1.35°C (2.43°F) below normal, the second coolest December on record, behind 1999. Overall, it was the coolest year for Australia since 2001, but was still 0.19°C above the 1961–1990 average. On a decadal scale, the years 2001–2010 were the warmest decade on record for the country."

Sources

* NASA, Jan 12, 2011 - NASA Research Finds 2010 Tied for Warmest Year on Record
* NOAA, Jan 12, 2011 - NOAA: 2010 Tied For Warmest Year on Record
* NOAA - State of the Climate Global Analysis Annual 2010