Climate change: How the crisis is affecting tornadoes

The series of weekend tornadoes that ripped through the parts of the US this weekend adds to another stretch of deadly and potentially unprecedented weather disasters that plagued the planet this year. Meteorologists and climate scientists say the latest outbreak is historic.

Global scientists made clear that weather events, no matter how severe, are occurring against the backdrop of human-caused climate change; nevertheless, it all comes down to discerning how a warming planet is altering weather patterns, including geographical location and frequency, as well as severity.

Victor Gensini, a professor at Northern Illinois University and one of the top tornado experts, said the weekend's outbreak is one of the most remarkable tornado events in US history -- and while climate change may have played a part in its violent behavior, it's not yet clear what that role was.

Think of a pair of dice, he said. On one of the die, you altered the value of five to six, which means it now has two sixes -- raising the chances of you rolling the pair of dice and getting the value 12. Although you can't immediately attribute that value of 12 to the change you made, you just altered the probability of that event occurring.

Gensini said that's similar to how the climate system now works -- the more humans pump greenhouse gases into the atmosphere and change the system, the chances of extreme weather events occurring will amplify.