100,000 years before the next glaciation?

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100,000 years before the next glaciation?

Postby HBS Guy » 16 Sep 2018, 09:31

https://www.nature.com/articles/nature16494

Published: 13 January 2016

Abstract

The past rapid growth of Northern Hemisphere continental ice sheets, which terminated warm and stable climate periods, is generally attributed to reduced summer insolation in boreal latitudes1,2,3. Yet such summer insolation is near to its minimum at present4, and there are no signs of a new ice age5. This challenges our understanding of the mechanisms driving glacial cycles and our ability to predict the next glacial inception6. Here we propose a critical functional relationship between boreal summer insolation and global carbon dioxide (CO2) concentration, which explains the beginning of the past eight glacial cycles and might anticipate future periods of glacial inception. Using an ensemble of simulations generated by an Earth system model of intermediate complexity constrained by palaeoclimatic data, we suggest that glacial inception was narrowly missed before the beginning of the Industrial Revolution. The missed inception can be accounted for by the combined effect of relatively high late-Holocene CO2 concentrations and the low orbital eccentricity of the Earth7. Additionally, our analysis suggests that even in the absence of human perturbations no substantial build-up of ice sheets would occur within the next several thousand years and that the current interglacial would probably last for another 50,000 years. However, moderate anthropogenic cumulative CO2 emissions of 1,000 to 1,500 gigatonnes of carbon will postpone the next glacial inception by at least 100,000 years8,9. Our simulations demonstrate that under natural conditions alone the Earth system would be expected to remain in the present delicately balanced interglacial climate state, steering clear of both large-scale glaciation of the Northern Hemisphere and its complete deglaciation, for an unusually long time.
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Re: 100,000 years before the next glaciation?

Postby HBS Guy » 16 Sep 2018, 09:38

So, low insolation (sunlight) in the Arctic Circle usually starts a major ice age. At present we have the low insolation—but no glaciation beginning. In fact, the Arctic Ocean, Greenland and Antarctica are all losing ice.

Temperatures had been dropping until the Industrial Revolution and glaciation could well have started but for the increase in CO2. The fact that the Earths orbit had been more circular is also another reason preventing glaciation. When it is more elliptical there are periods of less insolation when the planet is furthest away from the sun.


Other studies suggest there will be no glaciation for 50,000–100,000 years.
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Re: 100,000 years before the next glaciation?

Postby DonDeeHippy » 16 Sep 2018, 10:55

so no more glace cherries
Bongalong... for some reason women are just so superior to anything that ever existed or will ever exist!
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Re: 100,000 years before the next glaciation?

Postby HBS Guy » 16 Sep 2018, 12:13

No more snowballs either.
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