BEWARE THE GIGANTIC EARTH FART

Scientists think they have figured out what caused the unusual warmth of the Paleocene-Eocene Thermal Maximum some 55 million years ago:

"Basically, it looks like the Earth released a gigantic fart of green house gases into the atmosphere - and globally the Earth warmed by about 5C."

Appy Sluijs and his fellow scientists are, however, far from understanding the whole picture:

"We still haven't explained why the tropics stayed cool," Huber said. "Somehow, we have to explain how you can warm the poles up to 23 degrees Celsius without having the tropics rise to at least 50 degrees, which is 10 degrees too hot for plants to carry out photosynthesis."

He said the implications are troubling because current models may be providing optimistic predictions.

So, the coming human-induced warming might just be greater than predicted. Not necessarily:

"Today's models underpredict how warm the poles were back then, which tells you something disturbing — that the models, if anything, aren't sensitive enough to greenhouse gases," Huber said. "At the same time, it is possible that other forces in addition to higher-than-normal greenhouse gas concentrations were involved, otherwise we can't explain how the tropics maintained livable conditions.

Yep, scientists still have a lot of climate change explaining to do.