Some proponents of climate science are on a public relations drive to restore public confidence in the consensus that Earth is heating up, after critics seized on blizzards in the American Northeast, claiming they were evidence of global cooling.
Speaking to reporters, Jeff Masters, a meteorologist and founder of the web site, said that one extreme weather event, like a record-breaking snowfall, does not change the reality of climate change.
"Record snowstorms being evidence against global warming is just not true," said Masters, whose site gets 18 million visitors per month.
Various U.S. green groups and progressive organizations, including the , the and the , have similarly been working to clear the confusion surrounding the extreme freeze.
That's because from the other side of the debate, global warming skeptics in Washington have used the snowstorms to try to shore up their campaign against climate change legislation in Congress. Relatives of Sen. James Inhofe (R-Okla.), one of the nation's most vocal climate change deniers, built an igloo last week near the U.S. Capitol with a sign, "Honk if You [Heart] Global Warming."
Masters conceded that the heavy storms in the Northeast were "unprecedented" since modern temperature measurement began in 1880. But weather, which refers to day-to-day temperature, is not the same as climate, which includes other factors like humidity and precipitation over a long period of time.
Understanding whether the planet's temperature is on an upward path requires analysis of data going back three decades or more, he said.
For Masters and others, the long-term picture is clear: "The climate is changing, and it's warming," Masters said.
• According to numbers from the NASA Goddard Institute for Space Studies, global average surface temperatures have shot since 1880, with much of that jump occurring over the past 50 years.
• The World Meteorological Organization (WMO), a United Nations agency, said in December that the 10 years ending in 2009 was likely the on record. Previously, the hottest decade was the 1990s; before that it was the 1980s.
• In January, NASA announced that 2009 tied for the on record after 2005.
Despite the science, confusion over winter weather is threatening "to turn people away from thinking that global warming is real," said Masters.
Snowstorms Consistent With Warming?
Climate scientists across the spectrum agree on one thing — that a single extreme weather event, such as a cold spell, heat wave or flood, cannot prove or disprove climate change.
Some go father and insist that such extremes are consistent with a warming planet.
"Climate change projections show that a warming planet generates more precipitation in areas that typically experience rain or snow," said the (UCS), a private group that supports greenhouse gas regulation.