Guest eye roll by David Middleton
From Real Clear Science…
The Two Great Killers of ‘The Great Dying’
By Ross Pomeroy – RCP Staff
The Siberian Traps in northern Russia are picturesque. The expansive region is graced with serene slopes that jut into striking plateaus. Hiding behind this beauty, however, is a calamitous history, revealed by the basalt rock that underlies the region. Roughly 250 million-years-ago, the Siberian Traps exploded in a series of volcanic eruptions that continued off and on for two million years. When the upheaval finally concluded, 770,000 square miles of magma covered the land and an enormous amount of climate-altering gases had entered the atmosphere. As best scientists can tell, the global changes triggered by these gases resulted in the Permian–Triassic extinction event, “The Great Dying,” in which up to 96% of marine species and 70% of terrestrial vertebrate species disappeared. It was the worst mass extinction event in Earth’s history.
Simulating the global warming that occurred (as validated by geochemical data) during the Permian–Triassic extinction within a model of Earth’s climate, the researchers found that oxygen available in seawater to marine species would have fallen by 76 percent.
Could this calamitous scenario play out again given the current rate of ocean warming? Using publicly available IPCC data, the researchers estimated that by 2300, the oceans could warm to levels roughly ~35 to 50% of those required to account for most of the end-Permian extinctions. We may be on our way to a “Great Dying” sequel.
Source: Justin L. Penn, Curtis Deutsch, Jonathan L. Payne, Erik A. Sperling. “Temperature-dependent hypoxia explains biogeography and severity of end-Permian marine mass extinction.” Science. 7 Dec. 2018.
To paraphrase The Black Adder: “Ocean warming and oxygen deprivation stalk our oceans like… two giant stalking things.”
Ross Pomeroy is usually spot-on with his analyses of scientific studies. However, he tends to go off the rails when it comes to climate change. This was my comment on his article:
“Could this calamitous scenario play out again given the current rate of ocean warming? Using publicly available IPCC data, the researchers estimated that by 2300, the oceans could warm to levels roughly ~35 to 50% of those required to account for most of the end-Permian extinctions. We may be on our way to a “Great Dying” sequel.”
Only in an RCP8.5 fantasy land.
RCP8.5 yields a wide range of temperature increases by 2300. From 2 to 14 °C, with a mean value of 8 °C.
However, we know that RCP8.5 is 100% bull schist.
Temperature trends aren’t even on course to breaking out of the Quaternary noise level and 8 C probably doesn’t eve get us back to the Mid-Miocene Climatic Optimum.
And the Mid-Miocene Climatic Optimum was cooled than the Paleocene-Eocene Thermal Maximum and Early Eocene Climatic Optimum.
And the Early Eocene was a period of a explosive growth in biodiversity.
Could this calamitous scenario play out again given the current rate of ocean warming?
Christy, John. 2016. Testimony of John R. Christy. Washington, D.C.: U.S. House Committee on Science, Space and Technology, 23. https://ift.tt/2Qf9Z7w.
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IPCC, 2013: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change[Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp.
Wuebbles, D.J., D.W. Fahey, K.A. Hibbard, D.J. Dokken, B.C. Stewart, and T.K. Maycock. 2017. Climate Science Special Report: Fourth National Climate Assessment, Volume I. Washington, D.C.: USGCRP, 470. doi: 10.7930/J0J964J6.
Zachos, J. C., Pagani, M., Sloan, L. C., Thomas, E. & Billups, K. Trends, rhythms, and aberrations in global climate 65 Ma to present. Science 292, 686–-693 (2001).
via Watts Up With That?
December 7, 2018 at 08:49AM