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New Study Shows Three Abrupt Pulses of CO2 During Last Deglaciation
vinces99 writes A new study shows that the increase of atmospheric carbon dioxide that contributed to the end of the last ice age more than 10,000 years ago did not occur gradually but rather was characterized by three abrupt pulses. Scientists are not sure what caused these abrupt increases, during which carbon dioxide levels rose about 10 to 15 parts per million – or about 5 percent per episode – during a span of one to two centuries. It likely was a combination of factors, they say, including ocean circulation, changing wind patterns and terrestrial processes. The finding, published Oct. 30 in the journal Nature, casts new light on the mechanisms that take the Earth in and out of ice ages.
"We used to think that naturally occurring changes in carbon dioxide took place relatively slowly over the 10,000 years it took to move out of the last ice age," said lead author Shaun Marcott, who did the work as a postdoctoral researcher at Oregon State University and is now at the University of Wisconsin-Madison. "This abrupt, centennial-scale variability of CO2 appears to be a fundamental part of the global carbon cycle."
Previous research has hinted at the possibility that spikes in atmospheric carbon dioxide may have accelerated the last deglaciation, but that hypothesis had not been resolved, the researchers say. The key to the new finding is the analysis of an ice core from the West Antarctic that provided the scientists with an unprecedented glimpse into the past."
"We used to think that naturally occurring changes in carbon dioxide took place relatively slowly over the 10,000 years it took to move out of the last ice age," said lead author Shaun Marcott, who did the work as a postdoctoral researcher at Oregon State University and is now at the University of Wisconsin-Madison. "This abrupt, centennial-scale variability of CO2 appears to be a fundamental part of the global carbon cycle."
Previous research has hinted at the possibility that spikes in atmospheric carbon dioxide may have accelerated the last deglaciation, but that hypothesis had not been resolved, the researchers say. The key to the new finding is the analysis of an ice core from the West Antarctic that provided the scientists with an unprecedented glimpse into the past."
It happens a lot in science. Have you actually read "The Structure of Scientific Revolutions"? Clearly not.
Tubby or not tubby. Fat is the question
How do we know the CO2 spikes caused the warming? Perhaps the CO2 resulted from increased biological activity occuring as a result of the warming.
I would think increased biological activity would have sequestered CO2 rather than released it, but you could be right that the CO2 was a result of the warming. At the same time, we know that CO2 is a greenhouse gas, so (all else being equal) increased CO2 would result in higher temperatures. That's just physics. So possibly there is a feedback loop here.
While correlation doesn't in statistics imply causation, in this case we do have an understanding of the physics of the causal mechanism.
It's called the greenhouse effect.
I'm surprised you haven't heard of it.
No, it really has. You can do tabletop lab tests to confirm it. Earth only has one way to transfer energy to space, that makes it reaaaally fucking simple to work out the radiative transfer equations. A doubling of atmospheric carbon will provably, with utter certainty, result in ~3.7W/m^2 additional warming, commonly cited as 1 degree C global temperature increase. To what degree feedbacks (most importantly water vapor) increase this is a matter of some study, but that CO2 causes warming is exactly what people are referring to when they say "settled science". The only possible disproof would be to find another way to radiate energy, and that would be detectable by satellites. The "hockey stick" graph is neither here nor there, again, you can prove this with minimal lab equipment to your own satisfaction.
And for all those who argue we are burning too much fossil fuels, those carbon atoms weren't created into existence in the ground as they were today, unless you believe the earth is 6000 years old!
They were a part of the global carbon cycle, and buried during mass extinction events and processes that sequestered them to where they are today.
Ummm, close, but no. It was sequestered over hundreds of million years to billions of years but the bulk of the carbon from the carbon cycle is tied up in a few places, neither of which has anything to do with mass extinctions. The huge bulk of CO2 ( currently ~400PPM atmosphere, ~60*atmosphere dissolved in the oceans, and ~10,000*oceans+atmosphere is tied up in rocks ) is tied up in the carbonates, I.E. limestones and dolostones. Coals come from swamps, and oil comes from mostly shallow-ish marine bacteria that had periodic blooms and die-offs that settled into the sediments on the seafloor and got buried.
To err is human; effective mayhem requires the root password!