This post is by Lisa Moore, Ph.D., a scientist in the Climate and Air program at Environmental Defense.
Yesterday, an unusually ferocious winter tornado system killed at least 55 people in five Southern states, and destroyed over a thousand homes and businesses. Usually tornadoes touch down for 20 minutes then come back up, but these were rare "long-track" tornadoes that stayed on the ground for 30 to 50 miles.
Lots of recent research indicates that global warming increases the intensity of hurricanes. Could it also affect tornadoes? It’s too early to tell, but scientists are starting to look.