Showing posts with label tornadoes. Show all posts
Showing posts with label tornadoes. Show all posts

Friday, May 13, 2011

Welcome

A note to readers: It’s more than the shortage of quill pens and parchment that moves me to launch this late-blooming blog. After years on the smog beat as an environment writer, I’ve expanded my coverage to energy, which turns out to involve lots of technology. It also turns out to be fascinating.

Energy is the crossroads of the past and future, of belching 1920s smokestacks and biofuels made from algae. It’s embedded so deeply in daily life as to be invisible – until it’s not, when the next rate hike or power outage comes. It’s an engine of jobs and a casino of billion-dollar bets on technology that has to work. And a test of values: Will Americans choose the cheapest energy or the kindest to people and planet?

Come join the conversation, but play nice.

Let’s start with a topic we all can agree on: climate change!

It’s been a tough spring, I thought as hail pounded my expensive new roof the other night. Hundreds of tornadoes tore through the Southeast and Midwest, killing 24 people in North Carolina alone last month. The Mississippi is flooding middle-American towns and farms like something out of the Old Testament.

Is this what climate change looks like? Yes and no, says David Easterling, a scientist at the National Climatic Data Center in Asheville who studies extreme climate events.

“We’ve seen increases in heavy rainfall in the past, and that fits the climate models,” he says of the flooding. “Parts of the Midwest have seen that pattern.”

As air temperatures warm, the atmosphere holds more moisture that’s released as rain. Melting snow added to this year's deluges. North Dakota’s Red River is among those that “seem to have flooding just about every year,” Easterling says.

The two multi-year droughts the Carolinas have suffered in the past decade are also consistent with what’s expected of a warming climate, he said.

Tornadoes are another matter. While last month’s count could set a record, Easterling says it’s hard to compare activity to past years, when records relied solely on direct observations instead of modern tools such as Doppler radar.

Tornadoes form when a strong jet stream overhead and wind shear, the changes of speed or direction at different heights in the atmosphere, rotate thunderstorms. But climate models show wind shear will be less dramatic in the future.

“There really is not good evidence linking that to climate change,” he says.