"The bottoms of the clouds rise with warmer temperatures, while the top of the cloud stays the same so the clouds become thinner, " explained Del Genio.

CNN: Clouds' role in global warming studied

This should increase the current which normally flows from the top to the bottom of the atmosphere, charging up any clouds that lie in between.

ECONOMIST: Global warming

Some had suggested putting filters on top of skyscrapers to filter air pollution from the clouds, but were met with laughter.

CNN: STORY HIGHLIGHTS