Friday, April 22, 2011

Does Snow and Cold Weather Disprove Climate Change?


It’s Cold and My Car is Buried in Snow. Is Global Warming Really Happening?

Woman scrapes snow off of her car after cold weather and a snow stormFor years, climate contrarians have pointed to snowfall and cold weather to question the scientific reality of human-induced climate change.
Their annual barrage of misinformation obscures the interesting work scientists are doing to figure out just how climate change is affecting weather patterns year-round.
Understanding what scientists know about these effects can help us adapt. And, if we reduce the emissions that are driving climate change, we can avert its worst consequences in the future.

What is the relationship between weather and climate?

Weather is what’s happening outside the door right now; today a snowstorm or a thunderstorm is approaching. Climate, on the other hand, is the pattern of weather measured over decades.
NASA and NOAA plus research centers around the world track the global average temperature, and all conclude that Earth is warming. In fact, the past decade has been found to be the hottest since scientists started recording reliable data in the 1880s. These rising temperatures are caused primarily by an increase of heat-trapping emissions in the atmosphere created when we burn coal, oil, and gas to generate electricity, drive our cars, and fuel our businesses. Hotter air around the globe causes more water evaporation, which fuels heavier precipitation in the form of more intense rain and snow storms.
At the same time, because less of a region’s precipitation is falling in light storms and more of it in heavy storms, the risks of drought and wildfire are also greater. Ironically, higher air temperatures tend to produce intense drought periods punctuated by heavy floods, often in the same region.
These kinds of disasters may become a normal pattern in our everyday weather as levels of heat-trapping gases in the atmosphere continue to rise.
The United States is already experiencing more intense rain and snow storms. The amount of rain or snow falling in the heaviest one percent of storms has risen nearly 20 percent, averaged nationally—almost three times the rate of increase in total precipitation between 1958 and 2007.
Some regions of the country have seen as much as a 67 percent increase in the amount of rain or snow falling in the heaviest storms.