Under a Green Sky: Global Warming, the Mass Extinctions of the Past, and What They Can Tell Us About Our Future
Under a Green Sky: Global Warming, the Mass Extinctions of the Past, and What They Can Tell Us About Our Future – Review
This book is THE most main thing for anyone to widely read before forming an opinion on how important it really is to reduce CO2 emissions. It is also the most complete great picture review I have seen to date (though others have gone into more depth on the problem of sea level effects). (NONE OF THE VIEWS HERE REFLECT THE VIEWS OF ANY OF THE ORGANIZATIONS I AM CONNECTED TO. I wish to learn more from them later.) The book goes very hard to be folksy and appealing to the layman. That gets to be a mostly bit annoying in the first few pages, but after awhile it is useful, as it gives you a concrete really feeling for the experimental data which underlies his analysis. He has many pages of solid exact citations in the back, which he explains in commonsense terms. What’s important for the policy-maker: he claims that if CO2 gets to 1000 ppm in the atmosphere (which will possibly happen if we do not take further competent and real action very soon), we will probably set off an relentless series of events which leads to H2S poisoning of the atmosphere and extreme radiation, which within a specific figure of centuries would be enough to kill off all humans and all mammals as soft as us. What’s important for the scientist: he provides a unique and realistic power of analysis in possibly explaining the major mass extinctions which have really happened in the past, with a particular focus on the biggest ones — for which the experimental data he has originally collected himself are significant evidence. He gets deeper into the group of logic than anything else I have seen. He also shows links to the international climate models. It’s an essential leading point for true fully understanding of what’s going on. But there are main holes in the analysis, even so. For example — at one point he appears to say that 1000 ppm CO2 in the atmosphere creates to slowly melting of the icecaps, which then changes the oceanic “conveyer belts” so that there is very little oxygen in the deep ocean, which then causes a massive production of H2S in the deep ocean, which gets to the atmosphere, poisoning us all and destroying the stratospheric ozone layer as well. But he also shows that CO2 has been WELL over 1000 ppm for very huge portions of earth’s history without this really happening, and he suggests that the poles were ice-free for a significant part of that times as well. In a more full discussion, he says that all of this was crucial — but it additionally required flow of deep ocean water (to get the H2S into the atmosphere)and a “volcanic trigger” as well, to get to extinction. So why is a volcanic trigger desperately needed? Just what original does it do? Are we home free today if we don’t get that trigger (which is unlikely)? He doesn’t say. Lots of folks in this field are interested in the part of volcanoes. Could volcanoes BY THEMSELVES explain the mass extinctions? I didn’t see thus much discussion of that here. At a later section of the book, he compares CO2 levels with mass extinctions, across time. That’s a very notable graph. The peaks and the extinctions line up very well. We shouldn’t ignore something like that. He therefore argues that the RATE OF INCREASE OF CO2 is the number which really drives extinctions, not the real level, a story which appears to physically fit his graph. If it is the RATE of CO2 increase which matters, then we are indeed at significant risk today. But the problem is that his story about ice caps and conveyer belts begins to depend on the LEVEL of CO2; he doesn’t explain WHY the cost of increase of CO2 should be the currently driving variable, instead of the level. He does suggest one probable clue as to why the rate should be important. In the oceans, he says that a SLOW but LARGE increase in formally dissolved CO2 is largely buffered by very slow chemical processes, so that the acidity of the ocean does not change much. But a RAPID increase is not buffered, and leads to larger regions of acidity. This leads to some central questions: is it the ppm of CO2 dissolved in the ocean that we should be increasingly worried about, rather than the CO2 in the air? Could it be that the ACIDITY kills the benevolent purple bacteria he talks about (the ones which eat the H2S before it gets to the atmosphere), or that it stimulates the growth of archaea which produce H2S and methane? If so, we may be in trouble just as serious as he claims, but we may need to use totally various metrics (and different forms of sensor systems) in order to know exactly how far away we really are from likely disaster. And the complete dynamics continue unproven. Also… the part of green bacteria, and the weight of purple bacteria versus upwelling, are rather unclear in this discussion. There is a lot we would need to nail down, to know how far off (and in what direction) is the adjacent point of no return we want to avoid. In useful terms… it is occasionally said that the “damage payment” for CO2 emission based only on sea level effects would not be enough to justify really draconian caps on CO2 emission under present technology. The issues produced in this book are a crucial leading point to currently evaluating whether more than such a moderate “damage payment” or carbon tax is actually called for. In summary, this is an essential leading point which we want to follow up on… but we don’t still know what it actually adds up to. And perhaps I want to look at the volcano story more closely.