This post started as a response to a question on Quora. I spend way too much time on Quora and Facebook and other such time-vampire sites, but somehow I’ve worked up to the point where I’m a frequent responder on topics around climate change. I’ve become a most frequently-read poster ‘expert’ on Quora, which means… something.
Anyway, a question came up today that merits some exploration. And since I’ve never done a compilation of the estimates and predictions about NTHE, I thought this was as good a time as any.
“What events would take place in the months, weeks, days and hours leading up to a mass Extinction event?”
I am going by the work of scientists who’ve written about these events. These are not predictions, but estimates based on their research (which doesn’t include the word ‘prediction’). Most obvious scenarios first:
- loss of Arctic Summer ice. As president of Finland Niinistö says to whoever will listen to him, If we lose Arctic Ice, we lose the planet. The ice functions as the world’s air conditioner, and once the ice in the Northern Hemisphere is gone, both oceans and land surfaces will heat past the point where humans have habitat. If heating alone were the issue, that might leave humans with a decade or so, but heating sets off other feedback loops that will make things worse. related to this:
- heating past 3 C leading to death of human food crops—wheat and corn cannot germinate at the temperatures anticipated once the ice goes away. over 60% of human foodstuffs are based around wheat, with corn a close second. Humans would be gone within a few failed harvests;
- Ocean heating leading to mass death of phytoplankton—phytoplankton are the floor of the ocean food chain and provide almost half the world’s oxygen. Loss of phytoplankton means mass death of oxygen dependent creatures including humans. Also, mass death of oxygen dependent sea life will lead to massive plumes of sulfur dioxide, a highly poisonous gas. We already have places on the coast of Africa bubbling up with sulfur dioxide. Death from sulfur dioxide might take several years to unwind.
- Related to loss of ice: the ‘clathrate gun’ has been fired. Clathrates are the structures that sequester over a trillion tons of methane under the Arctic, and once they begin to destabilize due to warming waters, they will release huge amounts of methane. Arctic scientist Natalia Shakhova predicted that a 50 gigaton release of methane was thus possible ‘at any time’ and since Methane is a far more powerful greenhouse gas than carbon dioxide, such a release would be the equivalent of sudden release of 30 years of carbon dioxide. Earth temperatures would go up by several degrees within a matter of weeks. Heat ALONE could be enough to render humans extinct—some scientists are predicting that heat prostration driven by AGW could become the major source of death within a matter of a few years. Friend of this blog Kevin Hester posted about this a few years ago–
- Loss of permafrost in Siberia and other northern climes; melting permafrost is releasing millions of tons of GHG’s along with long-dormant bacteria that humans and other mammals may no longer have defenses to protect themselves from. Last year, , an Asian antelope, because warming temperatures made bacteria in their sinuses cause septic shock. The saiga have had such bacteria for millions of years. And an ancient plague released by warming might wipe out most of humanity within a matter of a few years.
Dr. Guy McPherson has kept a list of over four dozen such paths to human extinction. He has the list here: . The time lines are in some dispute. The Arctic Methane Emergency Group estimated that there were sufficient feedback paths in operation to drive the earth past 10.2 C above pre-industrial temperatures by 2026. Such heating would wipe out pretty much all our multi-celled animals. I’ve blogged about that here.
Two more paths to extinction not mentioned here. One is the collapse of industry. The Aerosol effect aka global dimming, is what happens when particulate from fossil fuels ends up in the upper atmosphere. It reflects sunlight out into space, and was understood after 9/11, when temperatures went up because commercial aircraft stopped flying. If we had a collapse of industrial civilization, the particulate would drop out and temperatures would go up by at least 1 C immediately. That would be well past the 2 C limit we ‘must not cross’ per most mainstream researchers.
The other problem is (still) Fukushima. All the surviving Nuclear Power Plants in the Fukushima complex have been made fragile by constant bombardment of the steel by neutrons. Another earthquake could topple these structures and release Extinction-levels of ionizing radiation. TEPCO (Tokyo Electric Power Company) has never been asked to give a timeline on remediation of the Fukushima accident, but the material will take a century or more to safely sequester. A full-blown release of all the radiation still there would probably lead to human extinction within a decade.
And finally–We could also still have a plain old nuclear war. No guesses on how that would play out, but we know that ionizing radiation could remove most multi-celled life from the planet for hundreds of thousands of years.
I hope this is useful. Oh yeah, happy holidays.