Global temperature data released today (9 July 2010) by NASA's Goddard Institute for Space Studies, show that the first half of 2010 was the warmest January-June period in the 130 year record (0.70oC above the long term mean; see figure below).  The warmth was especially pronounced in the Arctic.

Data for June show that it was the third warmest June on record globally, tied with 2005 at 0.59oC above the mean for 1951-1980.  The warmest June remains 1998 (0.69oC above the mean) followed by 2009 (0.62oC above the mean).  The warmth prevailed particularly in the Northern Hemisphere where the average of 0.78oC above the mean made June 2010 the warmest June on record. At 0.40oC above the mean, the Southern Hemisphere experienced its 8th warmest June (tied with 2001 and 2005).

In the Southern Hemisphere, the areas with the largest degree of warmth above the mean were the Antarctic Peninsula and northwestern South America.  In the Northern Hemisphere, positive anomalies were largest in the Arctic, the Southeastern U.S., central Africa, and the broad area stretching from the Black Sea to Northeastern China and Southeastern Russia.  In the Arctic, sea ice extent declined in June at a record pace for the month and had dropped to a record low for June (see our post Average Arctic Sea Ice Extent Drops to Record Low for the Month in June ). 

Further evidence of the warmth in the Northern Hemisphere is in data just released by the Rutgers University Global Snow Lab showing that snow cover in the Northern Hemisphere dropped to a record low for the month (see figure below) -- as it did in May (see our posting,  Northern Hemisphere Snow Cover Drops to Record Low for Month of May ).  

Accompanying the high monthly average temperatures were notable high temperature extremes over shorter time periods and specific geographic areas. Jeff Masters, who documented some of the extreme high temperatures in the Northern Hemisphere in his Wunderblog (see links under "Online Resources" below), said in a commentary on 24 June (emphasis added):

"We've now had seven countries in Asia and Africa that have beaten their all-time hottest temperature record during the past two months. As I discussed in my blog about Pakistan's May 26 record, Southeast Asia also had its all-time hottest temperature in May, when the mercury hit 47°C (116.6°F) in Myinmu, Myanmar on May 12. All of these records are unofficial, and will need to be certified by the World Meteorological Organization (WMO). According to Chris Burt, author of Extreme Weather, setting five national heat records in one month is not unprecedented--in August 2003, six countries (the UK, France, Portugal, Germany, Switzerland, and Liechtenstein) all broke their all-time heat records during that year's notorious summer heat wave. Fortunately, the residents of the countries affected by this week's heat wave are more adapted to extreme high temperatures, and we are not seeing the kind of death tolls experienced during the 2003 European heat wave (30,000 killed.) This week's heat wave in Africa and the Middle East is partially a consequence of the fact that Earth has now seen three straight months with its warmest temperatures on record..."

High temperatures were not the only phenomena driven partly by rising greenhouse gas concentrations in the atmosphere.  Changes in precipitation patterns, including the frequency and severity of extreme precipitation events, are occurring; and are projected to continue as climate is further disrupted. NOAA monitors and reports on these extremes on a monthly basis; see its June 2010 report. 

Heavy rain in southern China.  Source: NASA. See also China Flooding, June 2010 from NASA Goddard Space Flight Center.

Noteworthy too were record sea surface temperatures (SSTs) in the tropical Atlantic (see figure below), where the thermal energy contained in those surface waters is expected is fuel what forecasters expect to be one of the worst Atlantic hurricane seasons ever.  There is a long term trend of increasing SSTs in the tropical Atlantic and in the Gulf of Mexico, linked in part to rising atmospheric greenhouse gas concentrations.

"Map of monthly average Sea surface temperature (SST) anomalies (relative to 1961-1990) from HadSST2. White areas represent gridboxes containing no SST data. The black crosses and dashes indicate that a pixel is, respectively, the warmest or coldest example of that calendar month in the record."  Source: UK Met Office.

How you can help: The Senate is set to debate and vote on a climate & energy bill in the final weeks of July or early August (2010). Call your Senators and ask them to vote YES on a climate & energy bill that limits fossil fuel pollution.

Online WWF Resources Regarding U.S. Climate & Energy Policy

• U.S. Federal Policy section, WWF blog
• Act For Our Future
• What does the Spill have to do with a Climate Bill?

Online Resources:

NASA Goddard Institute for Space Studies, Surface Temperature Analysis:

• Global-mean monthly, seasonal, and annual means, 1880-present, updated through most recent month
• Northern Hemisphere-mean monthly, seasonal, and annual means, 1880-present, updated through most recent month
• Southern Hemisphere-mean monthly, seasonal, and annual means, 1880-present, updated through most recent month
• Zonal annual means, 1880-present, updated through most recent completed year

State of the Cimate > Global Hazards > June 2010.  From NOAA. Describes many of the weather extremes seen around the planet during June.

NASA Goddard Space Flight Center, Tropical Rainfall Measuring Mission (TRIMM), Extreme Events:

• Hurricane Alex, June-July 2010
• China Flooding, June 2010
• Tropical Cyclone Phet, May-June 2010

Jeff Masters' Wunderblog:

• Late Night Alex Update. Includes section on "East Asian heat wave continues." 28 June 2010.
• Tropical Storm Alex bears down on the Yucatan; extreme heat for Africa and Russia.  26 June 2010.
• 93L still disorganized; extreme heat wave hits the Middle East and Africa.  24 June 2010.

Driest Start for Decades.  Press release (7 July 2010) from the U.K. Met Office.

Global Surface Temperature Change [PDF].  June 1, 2010, draft paper by J. Hansen, R. Ruedy, M. Sato, and K. Lo (NASA Goddard Institute for Space Studies).  See also summary discussion of the paper, and two PowerPoint posters of key figures.

WWF Climate Change Blog:

• Long term Warming Trend Continues as U.S. Sees Much Above Normal Temperatures in June.  8 July 2010.
• Average Arctic Sea Ice Extent Drops to Record Low for the Month in June.  7 July 2010.
• Asia Saw Hottest Temperatures in its Recorded History in May .  17 June 2010.
• Records Toppled as NOAA Releases Latest Surface Temperature Data .  15 June 2010.
• NASA Reports Highest Spring Temperatures on Record as U.S. Senate Debates Climate Change.  10 June 2010.
• Above Normal Spring Temperatures in U.S. Continue Long-Term Upward Trend; Record Warmth in Northeast.  8 June 2010.
• Northern Hemisphere Snow Cover Drops to Record Low for Month of May.  7 June 2010
• NOAA Sees Potential for "Hyperactive" Hurricane Season; Record High Sea Surface Temperatures Among Contributing Factors .  1 June 2010.