It is all the fault of fluctuations in CO2. So says Peter Brannen in “The Ends of the World”. This is a terrific book even if you disagree with it, as I do, on no grounds I can think of except that he is a doomist.
Every few scores of millions of years, there have been massive exterminations of species. Brannen relates the best recent evidence for how these extinction events came about. There have been five of them, at least. Usually the underworld opens up and continents of lava spew forth, killing everything in their continent-sized lava flows, and what is not killed directly is then wiped out by ocean acidification (CO2 again). Or so much CO2 is belched out of the ground by volcanism that the planet gets too hot, such as 40C seas at the equator, which is hot-tub hot.
Obviously Brannen thinks that all of current human civilization is pumping massive amounts of CO2 into the atmosphere with such abrupt speed that nature has no chance of adapting to it.
It is not hard to find a paragraph that supports his contention.
As a result of this innovation [coal burning], human civilization is now propped up by a continuous explosion f energy, a global megametabolism, with hundreds of millions of years worth of sunlight being released all at once in combustion engines and power plants. Carbon dioxide is a by-product of this new civilizational metabolism, and we now emit 100 times more CO2 each years than volcanoes. This far outstrips the ability of the earth’s thermostat to keep up with rock weathering and ocean circulation, operating as those processes do on 1,000- to 100,000 year timescales. (at p. 236)
Nitrogen-fixing from the air, which is the technology that gives rise to artificial fertilizers, is also to blame for runoffs that take the oxygen out of seawater.
And it goes on. We are rapidly wrecking large parts of the planet, and he gives the reasons why this is so.
I must confess that Brannen makes my skepticism about the doomist view more difficult to maintain. However, he is well worth the effort, first because his science is good, second because he points out the enormous spans of time this planet has been around – spans so large that the earth has in effect been several different planets in the course of time – and third, because I think that every global warming/doomist skeptic needs to know the full argument, not just the IPCC version. Brannen has been hanging around with real scientists, not with atmospheric trend projectors and data falsifiers, such as NOAA and HadCrut and the IPCC pseudo-scientific international bureaucrats.
In my view, doomism is justified if we cannot get human population to shrink. There are several ways that the human race will make less impact on the planet in the next few hundred years.
Population reduction through lifestyle changes are already well underway. Everywhere women can guarantee that their children survive, they stop producing more than two children. See Hans Rosling on this issue.
The other traditional method is war, famine, pestilence and death. That is what will happen if we fail, and maybe it will happen anyway. If the world starts to go to hell through ecological disasters, war will inevitably follow, and with it the usual population correctives.
We could reduce population peacefully by conscious choices and end up in prosperity for the remaining few billions who will be found at the end of this process. We could reduce it by the Four Horsemen of the Apocalypse, and end up in a low productivity, high birthrate world, such as we began to get out of on the 18th century.
Maybe we are like bacteria on a Petri dish, and our numbers will expand until we die off catastrophically, as we exhaust our resources. That was the view of the biologist Lynn Margulis.
This question was also ably examined, in a more balanced way, by Charles C. Mann in his The Wizard and the Prophet. But Mann’s book, while more balanced than Brannen’s, deals with two scientists with two points of view, doomist and meliorist, whereas Brannen coneys a vast amount of information about how hellish the earth has been in the Great Extinctions that have ravaged the earth over time.
The disturbing aspect of Brannen’s argument is that, in his view, humans are acting as the unconscious agents of destruction. I do not see any happy outcome, but I hope I am spectacularly wrong.