(Presentation on Lake El’gygytgyn Findings Prior to Report Publication in Science)
A new study produced by polar researchers and published in the journal Science confirms a much warmer and mostly ice-free Arctic during periods when Earth’s atmospheric CO2 reached levels equivalent to those seen today.
The study took sediment cores from Russia’s lake El’gygytgyn (pronounced El-Gee-Git-Kin) in order to determine climate conditions north of the Arctic Circle during a period around 3.6-2.2 million years ago. During this time, atmospheric CO2 levels were comparable to those witnessed today. So the study may well be a strong allegory for what we should expect if human CO2 levels remain near the dangerously high 400 PPM level.
Lake El’gygytgyn was formed by an impact crater around 3.6 million years ago. It is a deep lake, so deep it would cover all but the top tip of the Washington Monument. For the first 20,000 years after its formation, there was little evidence of life found in sediment cores from the lake bottom. However, after this period, pollen from local plants began to emerge. Some, like Hemlock and Douglas Fir, tend to crop up in much more southern areas indicating that ice-free conditions predominated this extreme northern region.
Julie Brigham-Grette, a professor in the department of geosciences at the University of Massachusetts Amherst and lead author of the new study, which was published May 9 notes:
“To get Douglas fir and hemlock that far north of the Arctic Circle — you have to have pretty warm summers and warm winters in order for those trees to establish there… There was probably no sea ice, and the whole Arctic was pretty well forested, so it was a very different world.”
The researchers lead by Julie Brigham-Grette note that for such plants to be established in this region, temperatures would have been about 8 degrees Celsius hotter than today. These temperatures are consistent with a mostly ice-free Arctic environment.
This research, along with a growing body of Paleoclimate science, indicates that climate is much more sensitive to CO2 increase than current climate models may suggest. Overall, Paleoclimate may well be a far better determiner of the end result of human fossil fuel emissions than models which seek to pin down extraordinarily complex processes and are still in the early stages of development. And if past climate indicators do prove to be the best guide, sustained CO2 levels above 400 PPM will push for a long term temperature increase of around 3-4 degrees Celsius globally and 8-10 degrees at the poles. More importantly, these high levels appear to wipe out most ice in the Arctic environment.
Responses to current Paleoclimate research among the scientific community indicate a potential shift to reliance more on this data and less on models for future predictions. Kate Moran, an ocean engineer, notes:
“This new paleoclimate record adds to the growing evidence that Earth’s sensitivity to these levels of greenhouse gases may be higher than previously thought. Understanding Earth’s sensitivity is one of the key parameters for predicting future conditions of the planet under global warming.”
Such arguments aren’t merely academic. Ice loss in the Arctic is proceeding at a pace far exceeding previous predictions. Sea ice has melted by 80% since the early 1980s and rapid glacial melt is occurring in all regions of the Arctic. So we have past Paleoclimate evidence being validated by current Arctic trends which seem to point toward a far more rapid loss of polar ice than previously estimated.
Even more concerning, perhaps, is the fact that the Arctic is responding to CO2 levels of about 2-3 decades ago when CO2 was closer to 350 ppm. Because of natural inertia, the current CO2 levels of 400 ppm won’t begin to have full impact on the Arctic for another 20 years or so. And, in light of recent findings, that is a rather chilling prospect.
Gifford Miller, a professor in the department of geological sciences at the University of Colorado Boulder, who conducts research in the Canadian Arctic seems to agree:
“The ice is melting at all elevations,” Miller said. “Even if there is no additional warming, it’s only a matter of time before the ice is all gone.”
In the context of current business as usual fossil fuel emissions, these are substantial statements. If no additional warming is necessary to melt all the Arctic ice long-term, then what happens if CO2 levels increase to 1,000 PPM and temperatures rise to 6 degrees Celsius above average by the end of this Century? One can expect that under such extreme conditions, Arctic changes will be extraordinarily rapid and chaotic.
Links:
When the Arctic was 8 C Colder
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