David Brin ______________________________________________________________ Are we on the verge of an H2S Extinction Event? It is one of two ways that the gradual nature of human generated climate change might suddenly do a non-linear takeoff. (The other would be if deep ocean hydrates of methane suddenly reached a critical point and were to blurp - along with methane released from thawing tundra, sending the greenhouse skyrocketing.) Green-sky-ward Peter Ward (Under a Green Sky: Global Warming, the Mass Extinctions of the Past, and What they Can Tell us about our Future) and other researchers point to several past extinction events on Earth that seem to have been driven by sudden pollution of the atmosphere by hydrogen sulfide gas. This poison is generated in deep ocean anoxic (oxygen depleted) layers that stop getting mixing currents from above, by anaerobic archaeobacteria. ______________________________________________________________ DJS -- I can only judge this by the Permian-Triassic (PT) Mother of all Extinctions 252M Years Ago event (far worse than that which offed the dinosaurs etc., 66M years ago). In the PT event, a combination of one of the most massive volcano eruptions (Siberian Traps) in geological history, steadily rising water & land temperatures along with rising CO2/SO2 levels well, well beyond current levels, and no ice caps at all, produced an H2S rise from the deeps to destroy almost all species. This is so extreme from the current situation as to be absurd. The speed at which it is happening now is the only possibility of PT events resurrecting, and that is certainly remote. Ive certainly read no other AGW, however pessimistic, so much as whisper such a thing. ______________________________________________________________ A rapid rise in ocean acidity… check. This is the product of human-spewed CO2 that the denialists at Fox strenuously avoid mentioning. Because there is no response possible. Because the oceans are turning acid at unprecedented rates (? -- truly?). No Hannity-obfuscation can hide it… so they never ever ever mention it. And when the topic comes up? They point offscreen and yell… squirrel! ______________________________________________________________ DJS -- well, here I am much more in agreement. Increasing acidity and warming (non-fossil fuels needed here, which could be healthy by 2100), nutrient runoff, and up-welling of deep waters (not to mention over fising) disturbing and poisoning shallow waters are more worrisome. Even so, the author attributes this to, ...if we simply remain obstinately stupid and complacent. It is here he misses badly, for complacently and stupidity -- in the face of 21st century science, technology, and communications/ transportation -- or does he really believe we are as complacent and stupid as we were even a century ago let alone a millenium? Please read and study history before making overwhrought and blatantly false declarations. ______________________________________________________________ davidbrin.blogspot/2014/03/what-should-we-be-worried-about.html
Posted on: Mon, 10 Mar 2014 16:01:27 +0000
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