If anything, big snowstorms confirm -- not disprove -- global warming

For those who believe snowstorms disprove global warming global climate change, increased snowfall is actually a prediction of climate models and the logical outcome of warmer oceans.

National Public Radio reports:

Most [climatologists] don’t see a contradiction between a warming world and lots of snow. That includes Kevin Trenberth, a prominent climate scientist at the National Center for Atmospheric Research in Colorado.

“The fact that the oceans are warmer now than they were, say, 30 years ago means there’s about on average 4 percent more water vapor lurking around over the oceans than there was, say, in the 1970s,” he says.

Warmer water means more water vapor rises up into the air, and what goes up must come down.

“So one of the consequences of a warming ocean near a coastline like the East Coast and Washington, D.C., for instance, is that you can get dumped on with more snow partly as a consequence of global warming,” he says.

And Trenberth notes that you don’t need very cold temperatures to get big snow. In fact, when the mercury drops too low, it may be too cold to snow.

Increased snowfall is actually a prediction of climate models:

Increased snowfall fits a pattern suggested by many climate models, in which rising temperatures warm the world’s bodies of water, leading to more evaporation.

Climate scientists say the amount of atmospheric moisture has increased, which they predict will bring more rain in warmer conditions and more snow in freezing temperatures.

“All you need is cold air and moisture to meet each other” to make snow, said Jay Gulledge, senior scientist for the Pew Center on Global Climate Change. “And with global warming, the opportunities to do that should be more frequent.”

Besides, The Los Angeles Times notes:

The amount of recorded warming over the last century, about 1 degree Fahrenheit above preindustrial levels, is nowhere near enough to eradicate winter in the mid-Atlantic.

Also, weather is variable: The planet would have extreme highs and lows with or without an overall warming trend.

And for all the recent snow in Washington, it hasn’t been that cold — mostly in the 20s or low 30s. The average temperature in Washington in January, according to the National Climatic Data Center, was about a degree warmer than the average for the last 40 years.

But the reverse is also true: The fact that Vancouver, Canada, is experiencing record-high temperatures and importing snow for the Winter Olympics doesn’t prove a warming trend.

The articles also point out this is an El Nino year. And that means lots of precipitation.

Posted by James on Wednesday, February 17, 2010