Global Extinction within one Human Lifetime

[NoXion]

Global Extinction within one Human Lifetime as a Result of a Spreading Atmospheric Arctic Methane Heat wave and Surface Firestorm

Abstract

Although the sudden high rate Arctic methane increase at Svalbard in late 2010 data set applies to only a short time interval, similar sudden methane concentration peaks also occur at Barrow point and the effects of a major methane build-up has been observed using all the major scientific observation systems. Giant fountains/torches/plumes of methane entering the atmosphere up to 1 km across have been seen on the East Siberian Shelf. This methane eruption data is so consistent and aerially extensive that when combined with methane gas warming potentials, Permian extinction event temperatures and methane lifetime data it paints a frightening picture of the beginning of the now uncontrollable global warming induced destabilization of the subsea Arctic methane hydrates on the shelf and slope which started in late 2010. This process of methane release will accelerate exponentially, release huge quantities of methane into the atmosphere and lead to the demise of all life on earth before the middle of this century.

OK, this seems pretty fucking bad, but I'm not sure how I'd evaluate its likely veracity. Anyone know of or can give a second opinion?

[D.Turtle]

Global Extinction within one Human Lifetime as a Result of a Spreading Atmospheric Arctic Methane Heat wave and Surface Firestorm
This process of methane release will accelerate exponentially, release huge quantities of methane into the atmosphere and lead to the demise of all life on earth before the middle of this century.

OK, this seems pretty fucking bad, but I'm not sure how I'd evaluate its likely veracity. Anyone know of or can give a second opinion?

I shorted the OP to the important bit, I'm looking through the study now but the problem is the paper at least not in the ten minutes I was looking detailed a mechanism for this runaway methane to come from. There are methane pockets in the earth but there are not vast Methane reserves just waiting to be tapped and for this runaway effect to get started we kinda need large amounts of methane ready to go.

[Guardsman Bass]

According to Real Climate, it's extremely unlikely for that to happen:

Could there be a methane runaway feedback?.

The “runaway greenhouse effect” that planetary scientists and climatologists usually call by that name involves water vapor. A runaway greenhouse effect involving methane release (such as invoked here) is conceptually possible, but to get a spike of methane concentration in the air it would have to released more quickly than the 10-year lifetime of methane in the atmosphere. Otherwise what you’re talking about is elevated methane concentrations, reflecting the increased source, plus the radiative forcing of that accumulating CO2. It wouldn’t be a methane runaway greenhouse effect, it would be more akin to any other carbon release as CO2 to the atmosphere. This sounds like semantics, but it puts the methane system into the context of the CO2 system, where it belongs and where we can scale it.

So maybe by the end of the century in some reasonable scenario, perhaps 2000 Gton C could be released by human activity under some sort of business-as-usual scenario, and another 1000 Gton C could come from soil and methane hydrate release, as a worst case. We set up a model of the methane runaway greenhouse effect scenario, in which the methane hydrate inventory in the ocean responds to changing ocean temperature on some time scale, and the temperature responds to greenhouse gas concentrations in the air with another time scale (of about a millennium) (Archer and Buffett, 2005). If the hydrates released too much carbon, say two carbons from hydrates for every one carbon from fossil fuels, on a time scale that was too fast (say 1000 years instead of 10,000 years), the system could run away in the CO2 greenhouse mode described above. It wouldn’t matter too much if the carbon reached the atmosphere as methane or if it just oxidized to CO2 in the ocean and then partially degassed into the atmosphere a few centuries later.

The fact that the ice core records do not seem full of methane spikes due to high-latitude sources makes it seem like the real world is not as sensitive as we were able to set the model up to be. This is where my guess about a worst-case 1000 Gton from hydrates after 2000 Gton C from fossil fuels in the last paragraph comes from.

On the other hand, the deep ocean could ultimately (after a thousand years or so) warm up by several degrees in a business-as-usual scenario, which would make it warmer than it has been in millions of years. Since it takes millions of years to grow the hydrates, they have had time to grow in response to Earth’s relative cold of the past 10 million years or so. Also, the climate forcing from CO2 release is stronger now than it was millions of years ago when CO2 levels were higher, because of the band saturation effect of CO2 as a greenhouse gas. In short, if there was ever a good time to provoke a hydrate meltdown it would be now. But “now” in a geological sense, over thousands of years in the future, not really “now” in a human sense. The methane hydrates in the ocean, in cahoots with permafrost peats (which never get enough respect), could be a significant multiplier of the long tail of the CO2, but will probably not be a huge player in climate change in the coming century.

[The Duchess of Zeon]

The mere fact this article claims that a Permian event will result in the extinction of all life on earth when the historical Permian event did not (and in fact a large, pig-like early mammal predecessor ended up dominating the post-extinction world, i.e., a creature a lot like humans!) makes it sound utterly absurd and no one will take it seriously. Who could? Life went on and flowered and prospered again after the Permian.

[Lord of the Abyss]

A global firestorm wouldn't destroy all life on Earth even if it happened. There's life under water and life underground, even deep under the surface.

[Korto]

This process of methane release will accelerate exponentially, release huge quantities of methane into the atmosphere and lead to the demise of all life on earth before the middle of this century.

I'm with Lordy-boy. That's an idiotic claim, made in apparent total ignorance of the absolutely incredible variety of extreme environments colonized, and the sheer tenacity of life. Life in acid? Check. Temperatures above boiling-point? Check. Well below freezing? Check. Lives off volcanic gasses? Check. Haven't even remotely scratched the surface yet? Check.

[cosmicalstorm]

To actually sterilize the planet you would literally need to melt the entire solid crust into lava so that is not going to happen. To destabilize our civilization would take far less energy. So I could see this thing destroy what we have built so far, but not sterilizing the entire planet.

[Broomstick]

To actually sterilize the planet you would literally need to melt the entire solid crust into lava so that is not going to happen.

Oddly enough, that is sort of like what happened in Siberia during the time of the Permian extinction, resulting in the Siberian Traps. OK, it wasn't the whole world, but a substantial area did get covered in molten rock.

Anyhow - although the Permian Extinction may have been the worst extinction event so far it certainly did not wipe out all life on Earth. Major types of life, including land vertebrates, did survive. It no doubt sucked to an unimaginable degree to live through it, but the mere fact this article claims a total life wipe out makes me doubt the veracity of their claims.

But even if the situation was as bad as claimed - massive methane input to the atmosphere and 80 degree average global temperatures - it ignores the fact that there is an entire continent located at the South Pole that would be more moderate in temperature and could act as a refuge for larger lifeforms, and that unlike the critters of the Permian Era we might well have sufficient technology to allow for human survival (granted, at MUCH reduced numbers).

[cosmicalstorm]

A massive reduction in the human population within my own lifetime seems a lot more likely. I'm 29 so I would be so pessimistic as to say that I would be honestly surprised if there wasn't at least a disaster so big that it killed tens of millions of humans in a short time at some point in my lifetime. Hopefully not though.

[Simon_Jester]

Tens of millions, though, is not quite the scale we'd expect from a true civilization-threatening "global disaster" these days. Tens of millions of people die every year anyway, because we live on a planet with seven billion people and almost none of them live more than a hundred years.

Most of them die of what we consider natural causes, granted.

[Broomstick]

Just out of curiosity I did some Googling on the number of deaths per year. Looks like we're running around 56 million a year, so yeah, tens of millions of people die every year as part of ordinary life.

Seriously, unless you're talking about half a billion or more deaths in an event, it's not much of a statistical blip.

[Simon_Jester]

Well no; depending on where and how it happened it could be a really horrendous disaster. World War One only killed off about 1% of the human race, but the consequences defined most of the bad news of the 20th century.

But life and civilization went on. Somehow.

[Lord of the Abyss]

To actually sterilize the planet you would literally need to melt the entire solid crust into lava so that is not going to happen.

Oddly enough, that is sort of like what happened in Siberia during the time of the Permian extinction, resulting in the Siberian Traps. OK, it wasn't the whole world, but a substantial area did get covered in molten rock.

Which reminds me; there was IIRC a limited analogy to a "global firestorm" in prehistory. I recall reading that the Dinosaur Killer impact apparently hit at an acute angle, and as a result sent a horizontal blast & debris wave across the region that is now the Americas. Not a global firestorm, but a continent sized one seems like a good test case. The result was not the destruction of all life in the region; instead, it led to a disproportionate survival of species that spent a lot of time in the water or underground. So I'd expect something similar from the scenario in the OP.

[cosmicalstorm]

I'm aware that many humans die from various causes every year. What I was referring to was something like a tsunami, a meteorite impact in the hundred of meters size-range, a regional nuclear war between India and Pakistan or something along these lines. Looking back at the history of disasters it seems uncannily possible that something down that alley will happen at some point over the next 40 years. Sorry if I'm going OT now.