Stalin
Well-Known Member
- Joined
- Apr 4, 2008
- Messages
- 3,742
Daniel Rothman works on the top floor of the building that houses the Massachusetts Institute of Technology (MIT) Department of Earth, Atmospheric and Planetary Sciences, a big concrete domino that overlooks the Charles River in Cambridge, Massachusetts. Rothman is a mathematician interested in the behaviour of complex systems, and in the Earth he has found a worthy subject. Specifically, Rothman studies the behaviour of the planet’s carbon cycle deep in the Earth’s past, especially in those rare times it was pushed over a threshold and spun out of control, regaining its equilibrium only after hundreds of thousands of years. Seeing as it’s all carbon-based life here on Earth, these extreme disruptions to the carbon cycle express themselves as, and are better known as, “mass extinctions”.
Worryingly, in the past few decades geologists have discovered that many, if not most, of the mass extinctions of Earth history – including the very worst ever by far – were caused not by asteroids as they had expected, but by continent-spanning volcanic eruptions that injected catastrophic amounts of CO2 into the air and oceans.
Put enough CO2 into the system all at once, and push the life-sustaining carbon cycle far enough out of equilibrium, and it might escape into a sort of planetary failure mode, where processes intrinsic to the Earth itself take over, acting as positive feedback to release dramatically more carbon into the system. This subsequent release of carbon would send the planet off on a devastating 100-millennia excursion before regaining its composure. And it wouldn’t matter if CO2 were higher or lower than it is today, or whether the Earth was warmer or cooler as a result. It’s the rate of change in CO2 that gets you to Armageddon.
This is because the carbon cycle is happy to accommodate the steady stream of CO2 that issues from volcanoes over millions of years, as it moves between the air and oceans, gets recycled by the biosphere, and ultimately turns back into geology. In fact, this is the carbon cycle. But short-circuit this planetary process by overloading it with a truly huge slug of CO2 in a geologically brief timespan, beyond what the Earth can accommodate, and it may be possible to set off a runaway response that proves far more devastating than whatever catastrophe set off the whole episode in the first place. There could be a threshold that separates your run-of-the-mill warming episodes in Earth history – episodes that life nevertheless absorbs with good humour – from those that spiral uncontrollably toward mass extinction.
While it has been more than 60m years since the planet surpassed such a threshold, by Rothman’s calculation we are about to set the planet on just such an ancient and ominous trajectory, one that may take millennia to eventually arrive at the destination of mass extinction, but that may be all but inevitable once we have pushed off from shore.
It turns out that there are only a few known ways, demonstrated in the entire geologic history of the Earth, to liberate gigatons of carbon from the planet’s crust into the atmosphere. There are your once-every-50m-years-or-so spasms of large igneous province volcanism, on the one hand, and industrial capitalism, which, as far as we know, has only happened once, on the other.
www.theguardian.com
comrade stalin
moscow
Worryingly, in the past few decades geologists have discovered that many, if not most, of the mass extinctions of Earth history – including the very worst ever by far – were caused not by asteroids as they had expected, but by continent-spanning volcanic eruptions that injected catastrophic amounts of CO2 into the air and oceans.
Put enough CO2 into the system all at once, and push the life-sustaining carbon cycle far enough out of equilibrium, and it might escape into a sort of planetary failure mode, where processes intrinsic to the Earth itself take over, acting as positive feedback to release dramatically more carbon into the system. This subsequent release of carbon would send the planet off on a devastating 100-millennia excursion before regaining its composure. And it wouldn’t matter if CO2 were higher or lower than it is today, or whether the Earth was warmer or cooler as a result. It’s the rate of change in CO2 that gets you to Armageddon.
This is because the carbon cycle is happy to accommodate the steady stream of CO2 that issues from volcanoes over millions of years, as it moves between the air and oceans, gets recycled by the biosphere, and ultimately turns back into geology. In fact, this is the carbon cycle. But short-circuit this planetary process by overloading it with a truly huge slug of CO2 in a geologically brief timespan, beyond what the Earth can accommodate, and it may be possible to set off a runaway response that proves far more devastating than whatever catastrophe set off the whole episode in the first place. There could be a threshold that separates your run-of-the-mill warming episodes in Earth history – episodes that life nevertheless absorbs with good humour – from those that spiral uncontrollably toward mass extinction.
While it has been more than 60m years since the planet surpassed such a threshold, by Rothman’s calculation we are about to set the planet on just such an ancient and ominous trajectory, one that may take millennia to eventually arrive at the destination of mass extinction, but that may be all but inevitable once we have pushed off from shore.
It turns out that there are only a few known ways, demonstrated in the entire geologic history of the Earth, to liberate gigatons of carbon from the planet’s crust into the atmosphere. There are your once-every-50m-years-or-so spasms of large igneous province volcanism, on the one hand, and industrial capitalism, which, as far as we know, has only happened once, on the other.
‘A climate of unparalleled malevolence’: are we on our way to the sixth major mass extinction?
The long read: Churning quantities of carbon dioxide into the atmosphere at the rate we are going could lead the planet to another Great Dying
comrade stalin
moscow