It's disturbing to me that something as ever-present and non-controversial as the weather has become such a divisive tool in politics. Because the east coast, and Washington D.C. in particular, has suffered a massive winter storm this week, many climate change deniers have been using this circumscribed occurrence as gleeful evidence that global warming has been disproved (or has been a hoax all along). It is pure pigheaded ignorance to blatantly ignore science, as so many of these deniers are doing. And to what end? We all inhabit the same earth... if there is one issue on which all of humankind should be in agreement about it should be to protect and nurture the only home we have.
Thinking weather patterns through rationally and calmly, it is clear that an overall increase in the earth's temperature leads to warmer temperatures overall, and one "unusual" weather incidence in one location does not disprove a pervasive and global phenomenon. Mild temperatures and the effects of El Nino in the winter leads to increased evaporation of surface water, which leads to more water in the air. More water in the air leads to massive storms, including rains, and when the temperature drops below freezing, snow. Indeed, increased volatility and variability in weather patterns and cycles is one of the effects of climate change, leading to periods of extreme heat and extreme cold.
NASA has shown that 2009 was the second warmest year in modern record (2005 was the warmest), and that January 2000 to December 2009 was the warmest decade in the past 2000 years. The chart below (source: www.cru.uea.ac.uk/cru/info/warming/) shows average global temperatures from 1850 to 2008, where the dramatic rise in global temperature over the past twenty years comparative to the temperature fluctuations in the prior century, is obvious.
In addition, although December 2009 was unseasonably cool in North America (as climate change naysayers gleefully rubbed their mittened hands at such chilling temperatures, quipping childish jokes like, "what happened to that global warming? Can we get it back please...?") due to some unusual Arctic air pressure and jet stream effects, it's important to note that "the contiguous 48 states cover only 1.5% of the world area, so the U.S. temperature does not affect the global temperature much." said James Hansen, director of the Goddard Institute for Space Studies in NYC. It is undeniable that the average global temperature has increased by about 1.4 degrees F (or 0.8 degrees Celsius) since 1880 (and will keep increasing). This may not seem like much, but this supposed negligible change in global temperature could in fact result in the extinction of approximately 20-30% of the earth's species, if increases in global warming exceed 1.5-2.5 degrees celsius (relative to the average temperature from 1980-1999).
Bill Nye (the Science Guy) explains it all to Rachel Maddow: