Atmospheric CO2 Triggered a Global Warming Event 40 Million Years Ago
|Microfossils found in the drill cores.|
An interesting study suggests that CO2 has been a primary driver of Co2 in the past;
It is interesting to see that they determined a very similar climate sensitivity to Hansen, IPCC etc. The article concludes;
"The result, he says, will help climatologists get a better grip on the concept of climate sensitivity—the degree to which a global temperature increase is entirely dependent on an accompanying rise in CO2. The authors conclude that the climate sensitivity during the MECO led to a 2- to 5-degree C increase per doubling of atmospheric CO2.
The study does leave one big question outstanding: Where did all the MECO CO2 come from? This remains an area of speculation, Houben says, although scientists are fairly sure the source was not organic."One possibility I can think of that isn’t mentioned is Methane hydrate, an ice like combination of methane and water that forms in deep ocean. These have been studied as possible energy reserves by oil companies. There is now evidence that the methane in these can be released by events like undersea avalanches. These may have been the source of the massive Carbon Input During the Latest Paleocene Thermal Maximum.
"However the CO2 got there, the takeaway from this study is simple: "In the past," Zachos says, "whenever atmospheric carbon dioxide levels rise, the climate warms.""