It's known as the PETM. It's incredibly important to Climate Science because the High Arctic above 66°N warmed up by about +35°C.
Hot enough that alligators and palm trees lived around an ice-free Arctic Ocean that NEVER froze. Even in Winter.
Ask yourself how this is even possible based on what we know about the Climate System. Then you will start to understand how BAD things are.
The Earth’s Climate System — A Short Users Guide. Part 03.
The North Pole seems cold to us. But, 38% of the HEAT ENERGY that starts at the Equator winds up there, and STAYS.
What we didn’t know in 1998, was how the Climate System would respond to the additional HEAT ENERGY we were forcing into it.
There were three main theories.
1. The North Pole would just ‘eat’ the extra HEAT ENERGY.
2. The temperature at the North Pole would go up, “slightly”.
3. The temperature at the North Pole would go up, “A LOT”.
What was starting to scare Climate Scientists in 1998. Was that they had believed the answer would be #1 or #2, but fossil evidence indicated it was #3.
Under theories #1 and #2, atmospheric CO2 levels would have had to have been around 20,000ppm for temperatures in the Arctic to get that warm.
Even in 1998 there was NO EVIDENCE to support that idea. Instead, evidence was accumulating that indicated atmospheric CO2 levels had NEVER gone above 2,000ppm in over 500 million years.
Which meant that the “Climate Sensitivity” to CO2 had to be MUCH higher than they thought. Or, that temperatures in the Polar Zones, particularly in the Arctic, could increase “much more” and “much faster” than projected in the models.
