"Temperature rise has accelerated in recent decades," says Amy Heinzerling, Staff Researcher at the Earth Policy Institute, in a recent release, "Past Decade the Hottest on Record" "The earth's temperature is now 0.8 degrees Celsius (1.4 degrees Fahrenheit) higher than it was in the first decade of the twentieth century, and two-thirds of that increase has taken place since 1970."

Even with these seemingly small increases in global temperature, natural systems are already starting to respond, as evidenced by melting ice sheets and glaciers, shifting weather patterns, and changes in the timing of seasonal events. If temperatures continue to rise on their current trajectory, by the end of the century they will have left the narrow range in which human civilization has developed and flourished.

Though temperatures are rising around the globe, some areas are warming faster than others, with the greatest warming taking place in the Arctic. Paleoclimate records from Arctic lakes, tree rings, and ice cores reveal that the past decade was the warmest of the past two millennia. Warming is amplified in the Arctic for a number of reasons, including the loss of the region's extensive snow and ice cover: as temperatures rise and light-reflecting ice melts, it is replaced by darker water, which absorbs more energy from the sun, thereby accelerating warming. In parts of the Arctic, average annual temperatures have increased by as much as 2—3 degrees Celsius (3.6—5.4 degrees Fahrenheit) since the 1950s. In 2007, Arctic summer sea ice shrank to its lowest extent on record, leaving the Northwest Passage completely ice-free for the first time in human memory. Then 2008 and 2009 brought the second and third lowest extent of Arctic summer ice on record.

The earth's temperature is determined by a number of factors. One major influence is the El Nino—Southern Oscillation (ENSO). This cycle, which involves large shifts in atmospheric and ocean temperatures over the tropical Pacific, has two phases: El Nino, which typically raises average global temperature, and La Nina, which lowers it. Year-to-year temperature variations are also influenced by the amount of energy the earth receives from the sun: increases in solar activity tend to raise global temperatures, while decreases in solar activity lower them.

The past decade saw many record-breaking extreme weather events, providing examples of the kinds of incidents expected to become more frequent with global warming. In the summer of 2003, Europe experienced an intense heat wave that led to over 52,000 deaths. In the United States, where daily record high temperatures occurred twice as often as record lows over the last 10 years, persistent drought plagued parts of the South and West for much of the second half of the decade. A 2006 heat wave affecting the West and Midwest was blamed for 140 deaths in California. The 2005 Atlantic hurricane season was the worst on record, with 27 named storms, 15 of which were classified as hurricanes—including Hurricane Katrina, which caused over 1,300 deaths and $125 billion in financial losses.

In 2007, the Intergovernmental Panel on Climate Change (IPCC), an international body of over 2,500 scientists, released its Fourth Assessment Report, in which it called the recent warming of the globe "unequivocal." The report projected a rise in average global temperature of 1.1—6.4 degrees Celsius (2—11 degrees Fahrenheit) by the end of the century. Already, effects of increasing temperatures such as accelerating ice melt and sea level rise are outpacing the IPCC's predictions of just three years ago.  Without significant cuts in greenhouse gas emissions, global temperature will rise dramatically by the end of the century, creating a world that looks vastly different from the one we know today.

For full report visit http://www.earthpolicy.org/index.php?/indicators/C51/global_temperature_2010.

Contact Info: Media & Permissions to Reprint Contact:
Reah Janise Kauffman
Tel: (202) 496-9290 x 12
E-mail: rjk (at) earthpolicy.org
Research Contact:
Amy Heinzerling
Tel: (202) 496-9290 x 15
E-mail: aheinzerling (at) earthpolicy.org
Earth Policy Institute
1350 Connecticut Ave. NW, Suite 403                
Washington, DC  20036
Web: www.earthpolicy.org

Website : Earth Policy Institute