Surprise: The Last Ice Age was colder than anyone thought. Blame CO2!

We panic about the next half degree of warming (above the 1.5 we’ve already had) but the depth of the ice age was savagely cold. For years the experts told us what Earths temperature was then, but apparently they were wrong.

And yet corals and rainforest survived. Plus turtles, whales, kittens —  lots of things. And all without research grants.

KAst Glacial Maximum, Ice Age, show sheet. Earth.

Nobel gas proxy

Nice line on the Nobel gas calibration with ground temperatures. Nice proxy.

Two studies have come out in the last 10 months both showing that at its coldest point about 25,000 years ago, the Earth was on average six degrees cooler Celcius than it is today. And this new study includes estimates of temperatures of tropical land near the oceans which ought to be more stable and less prone to big extremes.

This comes from a newer style of proxy based on nobel gases dissolved in ground water. It appears to be quite an accurate proxy, judging by the graph to the right. And it solves a lot of problems with other proxies. We can take samples from all around the world instead of just the polar ice caps (like we can with ice cores). And it’s not dependent on living things which like higher CO2 levels and inconveniently move location as the climate changes.

It’s always worse than we thought

“The real significance of our paper is that prior work has badly underestimated the cooling in the last glacial period, which has low-balled estimates of the Earth’s  to ,” said paper co-author Jeffrey Severinghaus, a professor of geosciences at Scripps Institution of Oceanography, University of California San Diego. “The main reason that prior work was flawed was that it relied heavily on species abundances in the past. But just like humans, species tend to migrate to where the climate suits them.

The real significance is that 1. Experts are often wrong. 2. Real climate change is brutal. and 3. We don’t know when the next one is coming.

If this is right, all the other big names were not. But what’s two or three degrees between friends?

Extended Data Fig. 5 Comparison of AP2 LGM cooling estimates to literature values

Extended Data Fig. 5 Comparison of AP2 LGM cooling estimates to literature values

So the study finds that natural climate change is larger than anyone thought, and the next ice age is more scary than anyone realized, but this apparently means CO2 is more awful than ever. It seems the tropics can cool more than anyone thought, therefore they can also warm more than anyone expected. Got that? Because whatever happened, CO2 did it.

“The rather high climate sensitivity that our results suggest is not good news regarding future global warming, which may be stronger than expected using previous best estimates. In particular, our global review reinforces the finding of several single noble gas case studies that the tropics were substantially cooler during the last glacial maximum than at present. The unpleasant implication for the future is that the warmest regions of the world are not immune to further heating,” commented co-author Werner Aeschbach, a professor at the Institute of Environmental Physics, Heidelberg University, Heidelberg, Germany.

Of course, it all comes down to how these proxies are then used to guesstimate the effect of CO2 (while ignoring the effect of every other climate variable).

I’m not 100% sold on the deep cold and the new proxy. It’s not confidence building when researchers announce results in terms of CO2 when they didn’t have too. Confirmation bias?

Would you like more circular reasoning with those green colored glasses?

Thanks to obsessive Government funding, the point of every new proxy is to recalculate the “climate sensitivity” of  CO2, never to test the climate models, or calculate the effect of the sun, the moon or the effect of space weather on Earth. But they effectively are using a model to find a number that “shows models are right”. If solar-magnetic-wind-or-cosmic-factors affect the climate, the models (and researchers) are oblivious. Instead of finding “the sun did it” they will auto-attribute most of the Sun’s driving force to CO2 instead, because the models assume all those solar effects have zero effect on earths weather. And because the magic stardust of CO2 will always explain all the gaps, researchers will never find out how much influence the solar factors have because they aren’t looking.

The paper does broadly support a recent marine proxy study by Tierney et al. published last year that found substantially greater low-latitude cooling than previous efforts and, in turn, suggested greater climate sensitivity than prior studies. That earlier paper suggested the equilibrium response of Earth’s global-mean surface temperature is 3.4 degrees C per doubling of atmospheric carbon dioxide, in line with the consensus range of estimates from state-of-the-art climate models, but somewhat higher than the usual best estimate of 3.0 degrees C.

“The rather high climate sensitivity that our results suggest is not good news regarding future global warming, which may be stronger than expected using previous best estimates. In particular, our global review reinforces the finding of several single noble gas case studies that the tropics were substantially cooler during the last glacial maximum than at present. The unpleasant implication for the future is that the warmest regions of the world are not immune to further heating,” commented co-author Werner Aeschbach, a professor at the Institute of Environmental Physics, Heidelberg University, Heidelberg, Germany.

The ice sheets are coming back sometime:

This is where the ice got too last time around in the United Kingdom. What’s the plan for next time?

Lat Glacial Maximum, Ice Extent, UK, Map.

Last Glacial Maximum, Ice Extent, UK, Map.

REFERENCES

Seltzer, A.M., Ng, J., Aeschbach, W. et al. Widespread six degrees Celsius cooling on land during the Last Glacial Maximum. Nature 593, 228–232 (2021). doi.org/10.1038/s41586-021-03467-6

Jessica E. Tierney, Jiang Zhu, Jonathan King, Steven B. Malevich, Gregory J. Hakim, Christopher J. Poulsen. Glacial cooling and climate sensitivity revisited. Nature, 2020; 584 (7822): 569 DOI: 10.1038/s41586-020-2617-x

Britice project (Map of UK and Ireland)

By Ittiz – Own work, CC BY-SA 3.0, , CC BY-SA 3.0, Link

Last Glacial Maximum: https://ift.tt/3ycLYR0

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May 15, 2021 at 12:12PM

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