Bitter Winter Storms Consistent With Planetary Warming
Snowstorm: East Coast Blizzard Tied to Climate Change
Time Magazine, Feb. 10, 2010
As the blizzard-bound residents of the mid-Atlantic region get ready to dig themselves out of the third major storm of the season, they may stop to wonder two things: Why haven't we bothered to invest in a snow blower, and what happened to climate change? After all, it stands to reason that if the world is getting warmer - and the past decade was the hottest on record - major snowstorms should become a thing of the past, like PalmPilots and majority rule in the Senate. Certainly that's what the Virginia state Republican Party thinks: the GOP aired an ad last weekend that attacked two Democratic members of Congress for supporting the 2009 carbon-cap-and-trade bill, using the recent storms to cast doubt on global warming.
Brace yourselves now - this may be a case of politicians twisting the facts. There is some evidence that climate change could in fact make such massive snowstorms more common, even as the world continues to warm. As the meteorologist Jeff Masters points out in his excellent blog at Weather Underground, the two major storms that hit Philadelphia, Baltimore and Washington, D.C., this winter - in December and during the first weekend of February - are already among the 10 heaviest snowfalls those cities have ever recorded. The chance of that happening in the same winter is incredibly unlikely.
But there have been hints that it was coming. The 2009 U.S. Climate Impacts Report found that large-scale cold-weather storm systems have gradually tracked to the north in the U.S. over the past 50 years. While the frequency of storms in the middle latitudes has decreased as the climate has warmed, the intensity of those storms has increased. That's in part because of global warming - hotter air can hold more moisture, so when a storm gathers it can unleash massive amounts of snow. Colder air, by contrast, is drier; if we were in a truly vicious cold snap, like the one that occurred over much of the East Coast during parts of January, we would be unlikely to see heavy snowfall.
Climate models also suggest that while global warming may not make hurricanes more common, it could well intensify the storms that do occur and make them more destructive.
But as far as winter storms go, shouldn't climate change make it too warm for snow to fall? Eventually that is likely to happen - but probably not for a while. In the meantime, warmer air could be supercharged with moisture and, as long as the temperature remains below 32°F, it will result in blizzards rather than drenching winter rainstorms. And while the mid-Atlantic has borne the brunt of the snowfall so far this winter, areas near lakes may get hit even worse. As global temperatures have risen, the winter ice cover over the Great Lakes has shrunk, which has led to even more moisture in the atmosphere and more snow in the already hard-hit Great Lakes region, according to a 2003 study in the Journal of Climate.
Ultimately, however, it's a mistake to use any one storm - or even a season's worth of storms - to disprove climate change (or to prove it; some environmentalists have wrongly tied the lack of snow in Vancouver, the site of the Winter Olympic Games, which begin this week, to global warming). Weather is what will happen next weekend; climate is what will happen over the next decades and centuries. And while our ability to predict the former has become reasonably reliable, scientists are still a long way from being able to make accurate projections about the future of the global climate. Of course, that doesn't help you much when you're trying to locate your car under a foot of powder.
Amidst Global Warming Coldest Winter in 50 Years
Inter-Press, Feb. 11, 2010
BERLIN, Feb 11 (IPS) - It was probably an irony that Europe's coldest winter in 50 years coincided with the U.N. climate change summit in Copenhagen last December, which failed to deliver a treaty to reduce global warming emissions.
Since Dec. 13 it has been snowing uninterruptedly in Northern Europe. In some places in Germany, average night temperature has been around minus 20 degrees Celsius. The arctic winter, the coldest since 1957, froze rivers and channels, and disrupted transport links to some islands in the Baltic Sea.
The winter has also taken a toll on human lives. In Poland alone at least 212 people have died since November. Victims of cold In Germany, 14 people are known to have died during January, and hospitals around the country are reporting thousands of winter-related accidents - from auto crashes to people who simply slip on the frozen sidewalks and suffer fractures.
Similar severe weather conditions have been reported in Eastern Europe, in Central Asia and in North America.
But the arctic winter - the second this decade - is an exception to the general trend of global warming, according to meteorologists and climate experts. Frank Boettcher, director of the German Institute for Weather and Climate Communication, told IPS that "the present winter does not contradict the global climate change trend at all."
As indicator of the persistence of climate change, Boettcher referred to the present temperatures in Greenland. "Right now, temperatures in Greenland are 15 degrees Celsius above the season's long-term average," he said. "This is a good indicator that we cannot rationalise global warming away."
Boettcher said that the present temperatures in Central and Northern Europe are relatively low. ‘’That's why many consider the winter particularly cold. But, in general, average temperatures have been on the rise since many years."
According to official German weather statistics, present average temperature is at least one Celsius higher than 100 years ago. Even more illustrative is the comparison of the so-called cold sum of the winter, which is the total of all the daily negative average temperatures measured in the period between Nov. 1 and Mar. 31.
During the winter of 2009, the cold sum amounted to 131 - in 1946, last century's coldest winter, the value surpassed 500 points. According to the German weather station of Zwickau, some 200 km south of Berlin, so far the cold sum of this winter has reached 225.
Uwe Kirsche, spokesperson of the German weather service, also said that even if the present weather conditions appear very cold, "it is the long-term observations which are important. This winter, even if it appears to be particularly cold and particularly long, it does not contradict the long-term evidence of global warming."
Kirsche referred to a report by the U.S. National Aeronautics and Space Administration (NASA), which confirmed that the present decade has been the warmest ever observed in the southern hemisphere.
The NASA report released Jan. 21, said that new analysis of global surface temperatures found that 2009 was the second warmest since 1880. "In the southern hemisphere, 2009 was the warmest year on record," it said.
The report explained that 2008 was the coolest year of the decade in the southern hemisphere due to a strong La Nina phenomenon, which cooled the tropical Pacific Ocean below average temperatures. La Niña (the little girl) is a coupled ocean-atmosphere phenomenon similar to El Niño.
During La Niña, sea surface temperature across the equatorial Eastern Central Pacific Ocean is lower than normal by 0.5 degrees Celsius. In the United States, an episode of La Niña is defined as a period of at least five months of La Niña conditions.
In its report, the NASA said that "2009 saw a return to near-record [high] global temperatures as the La Nina diminished, according to the new analysis by NASA's Goddard Institute for Space Studies (GISS) in New York."
The document also confirmed the trend seen elsewhere, that this decade has been the warmest ever. In the paper, NASA points out that the 2009 average temperatures were a small fraction of a degree lower than 2005, the warmest on record.
That puts 2009 in a tie with a cluster of other recent years - 1998, 2002, 2003, 2006, and 2007 - as the second warmest on record.
"There's always interest in the annual temperature numbers and a given year's ranking, but the ranking often misses the point," said James Hansen, GISS director, according to a NASA press release. "There's substantial year-to-year variability of global temperature caused by the tropical El Nino-La Nina cycle."
"When we average temperature over five or ten years to minimise that variability, we find global warming is continuing unabated," Hansen concluded. According to GISS data, during the past three decades, there has been an upward trend in world average temperatures of about 0.2 degrees Celsius per decade. In total, average global temperatures have increased by about 0.8 degrees Celsius since 1880.
This data is consistent with observations by the U.N. weather agency, the World Meteorological Organisation (WMO). Just ahead of the Copenhagen conference , the WMO said that the past ten years had been the warmest since records began in 1850.
The decade 2000-2009 "is very likely to be the warmest on record, warmer than the 1990s, than the 1980s and so on," Michel Jarraud, secretary-general of the WMO, told a news conference at the Danish capital on Dec. 8.
Other than average temperatures, evidence of global warming is manifold, from the bleaching of coral reefs to the melting of glaciers in several regions of the world, and to the acidification of ocean waters and their continued rise in level.
And yet, the present European cold winter will continue until March, according to the German weather forecast service. "The cold air is this time obstinate," meteorologist Dominik Jung told IPS. "There is a stable thick cold air mass over Northern Europe, which is being constantly driven towards the South. It is going to be cold for the weeks to come."