Bill Nye: 'Heat energy' caused 2.6 mile-wide tornado in Oklahoma

Excess "heat energy in the atmosphere" contributed significantly to making last week's EF5 tornado in El Reno, Oklahoma grow to an astonishing 2.6 miles-wide, science educator Bill Nye told CNN on Tuesday.

The El Reno tornado was the widest-ever on record, and the National Weather Service said its winds nearly topped 300 miles per hour. A total of 19 people died in the event, including two experienced storm chasers, less than two weeks after another EF5 tornado killed 25 in neighboring Moore, Oklahoma.

"What would make it so wide is more heat energy in the atmosphere," Nye said. "But just fundamentally, if you think of a tornado as being a half mile or three quarters of a mile wide, this thing's about four times that... So, the first approximation is, if it's four times as wide and you're looking at the same area, it would be 16 times as much energy [as an average tornado]."

"Now, the problem is probably more complicated than that," he went on. "But it's on the order of two times 10: so 20 times as much energy in a tornado. And you guys, I appreciate everybody saying 'this is a very rare event, you may never see this again in your lifetime,' but if this is the third tornado to go through, very narrowly, this track in the last, say, since 1999... Maybe it's the beginning of something that's troublesome. So, this is really something for everybody to consider."

While the science is out on how climate change interacts with tornadoes, scientists have long predicted that extreme weather patterns would worsen as more heat energy and moisture is trapped in the atmosphere due to human activity and industrial carbon emissions.

In his 2009 book "Storms of My Grandchildren," former top NASA climatologist James Hansen writes that as the polar ice caps melt, more water vapor occupies the air. With more water vapor and more heat trapped in the atmosphere, extreme weather systems like tornadoes and hurricanes have more moisture to power their fury, leading to storms of gradually increasing destructiveness.

"Global warming does increase the intensity of droughts and heat waves, and thus the area of forest fires," Hansen wrote. "However, because the warmer atmosphere holds more water vapor, global warming must also increase the intensity of the other extreme of the hydrologic cycle -- meaning heavier rains, more extreme floods, and more intense storms driven by latent heat, including thunderstorms, tornadoes, and tropical storms."

Climate-related extreme weather events cost the U.S. in excess of $170 billion in 2012, a total which amounts to more than two-thirds of the natural disaster costs felt around the world, according to the environmental group World Watch Institute.

This video is from CNN, aired Tuesday, June 4, 2013.