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Apologize in advance if this is a silly question but… Is it fair to assume the earth is a closed loop self healing system? That is even if we dump a lot of ba

by lgkk 3y ago

Apologize in advance if this is a silly question but… Is it fair to assume the earth is a closed loop self healing system? That is even if we dump a lot of bad stuff into the atmosphere, the planet will eventually “equalize” to “normal” levels. I would rather we did not of course. I’m just curious about the planetary atmospheric system.

nathanfig 3y ago
Not really. The ocean serves as a natural carbon sink to a degree- but this is acidifying the ocean. And some feedback loops accelerate rather than decelerate warming- such as ice loss decreasing albedo. Life on Earth can adapt to a new normal, certainly, and on a geological timescale normal has shifted many times. Humans will adapt too, but will likely endure catastrophic losses on the way.
chris_va 3y ago
Very simplified (ocean-centric) homeostat: The surface of the ocean is in equilibrium with the atmosphere, so increasing atmospheric ppm increase the ppm of CO2 in the mix layer (think of it as a gas sponge). The ocean buffers that co2 (carbonate/bicarbonate system), so the amount of carbon there is a lot higher than just 420ppm, and in doing so it becomes slightly more acidic. As the ocean turns over (every ~5000 years), it brings that acidity down to depth where it can react with various forms of alkalinity that are at down there (mafic rock at the bottom of the ocean, sediment, etc), partially neutralizing it. It takes about 20 cycles (very slow) to do this, so ~100k years to return to a pre-industrial level. The pre-industrial ppm is defined mostly by biology. A more complicated treatment of the carbon cycle: https://www.ipcc.ch/site/assets/uploads/2018/02/TAR-03.pdf https://www.ipcc.ch/site/assets/uploads/2018/02/TAR-03.pdf
ggpsv 3y ago
The assumption you're making here is that the Earth "heals", as if a wound has been inflicted. Likewise, that there is a "normal" level. In other words, that there is a prevailing state to which the system returns to, or must return to. I invite you to question that assumption first and foremost. You must think of the Earth more as a process than a fixed thing. Thinking about this system in terms of feedback loops may be more helpful here. Drastically increasing C02 levels affects several feedback loops in the system, essentially transitioning it to a state that is different to the current one. As noted elsewhere in the comments, the Earth has gone through different eras in which the atmosphere had "high" and "low" levels of C02.
mempko 3y ago
There is absolutely no reason to assume it's a 'self-healing' system.
Chabsff 3y ago
It is fair to assume that it'll eventually stabilize at some, probably meta-stable, equilibrium.

by lgkk 3y ago

nathanfig 3y ago

Not really. The ocean serves as a natural carbon sink to a degree- but this is acidifying the ocean. And some feedback loops accelerate rather than decelerate warming- such as ice loss decreasing albedo. Life on Earth can adapt to a new normal, certainly, and on a geological timescale normal has shifted many times. Humans will adapt too, but will likely endure catastrophic losses on the way.

chris_va 3y ago

Very simplified (ocean-centric) homeostat: The surface of the ocean is in equilibrium with the atmosphere, so increasing atmospheric ppm increase the ppm of CO2 in the mix layer (think of it as a gas sponge). The ocean buffers that co2 (carbonate/bicarbonate system), so the amount of carbon there is a lot higher than just 420ppm, and in doing so it becomes slightly more acidic. As the ocean turns over (every ~5000 years), it brings that acidity down to depth where it can react with various forms of alkalinity that are at down there (mafic rock at the bottom of the ocean, sediment, etc), partially neutralizing it. It takes about 20 cycles (very slow) to do this, so ~100k years to return to a pre-industrial level. The pre-industrial ppm is defined mostly by biology. A more complicated treatment of the carbon cycle: https://www.ipcc.ch/site/assets/uploads/2018/02/TAR-03.pdf https://www.ipcc.ch/site/assets/uploads/2018/02/TAR-03.pdf

ggpsv 3y ago

The assumption you're making here is that the Earth "heals", as if a wound has been inflicted. Likewise, that there is a "normal" level. In other words, that there is a prevailing state to which the system returns to, or must return to. I invite you to question that assumption first and foremost. You must think of the Earth more as a process than a fixed thing. Thinking about this system in terms of feedback loops may be more helpful here. Drastically increasing C02 levels affects several feedback loops in the system, essentially transitioning it to a state that is different to the current one. As noted elsewhere in the comments, the Earth has gone through different eras in which the atmosphere had "high" and "low" levels of C02.

mempko 3y ago

There is absolutely no reason to assume it's a 'self-healing' system.

Chabsff 3y ago

It is fair to assume that it'll eventually stabilize at some, probably meta-stable, equilibrium.