Climate Cast: Stronger blizzards in a warmer world?

The water cooler and twitter-sphere is still abuzz this week over the massive #Blizzard of 2015.

The storm smashed all time snowfall records near Boston, and smashed homes along the Massachusetts coast.

Blizzards and climate change?

Many questions still swirl as the storm reverberations fade.

How good was the forecast? Which models handled the storm best? Did warmer than average Atlantic Ocean water temperatures play a role in turbocharging the storm? How can climate change contribute to stronger blizzards?

All good questions. Here are some answers.

PBS Frontline tackles blizzards and climate change in their series Climate of Doubt.

With every winter storm, including the blizzard hitting the Northeast this week, climate change skeptics return to a familiar argument: If the world is getting warmer, why am I stuck out here, shoveling so much snow?

Climate scientists tell FRONTLINE that blizzards don’t refute evidence of climate change — in fact, climate change can make blizzards more intense.  The first thing people need to understand, they say, is the difference between climate and weather.

Why does climate change lead to more moisture?

“The maximum amount of water vapor that can be present increases with increasing temperatures. That’s just a consequence of the laws of physics,” Broccoli said.

Global sea temperatures have gone up about one degree Fahrenheit since the 1970s because of human activity, said Kevin Trenberth, a distinguished senior scientist in climate analysis at the National Center for Atmospheric Research.

The higher sea temperatures lead to higher temperatures above the sea surface. That warmth moves throughout the year, and at this time of year, gathers off the East Coast.

“If we have a storm that’s developing, it reaches out as far as a thousand miles away and grabs the available moisture, and brings it into the storm so that it snows harder,” Trenberth said. “At this time of year, this is exactly what you expect.”

Warmer Oceans: Fuel for storms

We know warmer oceans release more heat into storms. How much of that can we attribute to climate change? Think Progress Climate talked to NCAR's Kevin Trenberth, who some eye catching perspective on how warm waters helped fuel the Blizzard of 2015.

Another epic blizzard is bearing down on New England. There is a “big part” played by “human-induced climate change,” especially warming-fueled ocean temperatures, according to Dr. Kevin Trenberth, former head of the Climate Analysis Section at the National Center for Atmospheric Research.

I asked Dr. Trenberth to comment on the role climate change has on this latest storm, which is forecast to set records. He explained:

The number 1 cause of this is that it is winter. In winter it is cold over the continent. But it is warm over the oceans and the contrast between the cold continent and the warm Gulf Stream and surrounding waters is increasing. At present sea surface temperatures are more the 2F above normal over huge expanses (1000 miles) off the east coast and water vapor in the atmosphere is about 10% higher as a result. About half of this can be attributed to climate change.

Milder winters: Still cold enough for big snow

Even as winter trend milder overall, it's still usually cold enough to produce snow.

It may seem counter-intuitive, but a warmer planet actually pumps more moisture into he atmosphere to fuel storms, even in winter. Here's a look at how that happens from Climate Central.

https://www.youtube.com/watch?v=r8oVoXaLRL0#t=99

An increasing number of weather and climate experts point out that all weather is now flavored in some way by climate change. The rapid "bombogenesis" development and ferocity of the Blizzard of 2015 will likely be the subject of future attribution studies. Did a warmer Atlantic Ocean play a role in juicing storm intensity and contribute to record snowfall totals?

The evidence is growing that it did.