Tag Archives: The great dying

Volcanism does not cause glaciations; let’s turn this statement on its head

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Is there a relationship between volcanism and glaciation?

It is almost a truism that volcanic eruptions influence climate. Cold winters and even failed crops, particularly in the northern hemisphere, followed on the heels the Tambora, Krakatoa, and Pinatubo eruptions.  But these climate aberrations were relatively short-lived, counted in years; the stratospheric aerosols and fine volcanic ash that reflect solar radiation back into space, eventually succumb to gravity and fall to earth.  Eruptions of this kind do not result in long-lived, or permanent changes; they are temporary blips on an evolving earth and an evolving climate. Continue reading

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The (not so) Great Dying; Permian extinctions

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Ernst Haekel's lithograph of Rugose corals

The great end of Permian extinction

It seems that global catastrophes and the ensuing mass extinction of all manner of life-forms, asteroid impacts and Dinosaurs immediately come to mind, were made for Popular Science.  Even Hollywood is in on the act.  Perhaps it’s because, in the telling, they appeal to some innate sense of nihilism, a bit like the existential threats that politicians trot out from time to time.

A recent scientific paper by Steven Stanley published by the US National Academy of Sciences, provides some good news on this score; past estimates of life forms snuffed out by such global events, have been exaggerated.  Stanley’s reassessment accounts for the fact that extinctions are taking place all the time, in the background, and that these individual, long-term biotic events need to be subtracted from the total species loss resulting from some catastrophe.  Continue reading

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