5 ms·

Dropping Oxygen Will Eventually Suffocate Most Life on Earth

12 points by gabea 5y ago

rsj_hn 5y ago
This seems a bit clickbaity, as it's just a model that points out that rather than the sun burning up the earth as it expands, the increasing cosmic rays will first split apart CO2 and lead to a loss of oxygen from the atmosphere. Sort of like saying "it's the fall that will kill you". Both scenarios are pretty far off and not deserving of such an alarming headline.
rektide 5y ago
We talk about CO2 all the time but the ongoing combined de-oxygenation and acidification of the oceans & bodies of water seems like such a vastly more real present & immediate threat to me. This article's looking at more radical, longer term shifts. But we are already well well well into the suffocation of the sea. And there's a lot of sea we're suffocating.
jefurii 5y ago
From TFA: "probably won't happen for another billion years or so".
LinuxBender 5y ago
This probably won't happen for another billion years or so. But when the change comes, it's going to happen fairly rapidly, the study from earlier this year suggests. I would really hope that within a billion years we have managed to find other planets, built massive cities or worlds in space especially given the potential collision courses with other galaxies around 1.9 billion years and the expansion of the star we call the sun that will eventually engulf the earth evaporating all the water.
brian-armstrong 5y ago
The abstract has a few more details >>> We find that future deoxygenation is an inevitable consequence of increasing solar fluxes, whereas its precise timing is modulated by the exchange flux of reducing power between the mantle and the ocean–atmosphere–crust system. Our results suggest that the planetary carbonate–silicate cycle will tend to lead to terminally CO2-limited biospheres and rapid atmospheric deoxygenation, emphasizing the need for robust atmospheric biosignatures applicable to weakly oxygenated and anoxic exoplanet atmospheres and highlighting the potential importance of atmospheric organic haze during the terminal stages of planetary habitability.
lholden 5y ago
Not really explained by the linked article, but my understanding is that as the Sun increases in luminosity (increasing the solar flux), the chemical reactions that binds CO2 will increase. Within 500-600 million years the CO2 levels drop beyond the point for C3 photosynthesis. Plants using C4 photosynthesis will survive for about twice as long, though by that point the increased solar flux will have caused the surface temperature on Earth to be uninhabitable anyways. Of course, who really knows how life might evolve to adapt to these changes. Humans have been pretty good at liberating carbon for instance :P.
- entropicgravity 5y ago
  We should be living on Mars by then and it will have warmed up comfortably.
kaminar 5y ago
Let's just say Bill Gates is already working on it...
K0balt 5y ago
So this implies then that the “Goldilocks”phase of earthlike planets in general may be shorter than thought. It is interesting to me that in the long view, the ability to terraform or colonize space/other worlds turns out to be a survival gate for life forms.
K0balt 5y ago
It would be interesting to see if there is fossil fuel money somewhere behind this article. This is exactly the kind of information that climate change deniers grab onto (“if we run out of co2 we are all doomed! More co2 is better!)

12 points by gabea 5y ago

This seems a bit clickbaity, as it's just a model that points out that rather than the sun burning up the earth as it expands, the increasing cosmic rays will first split apart CO2 and lead to a loss of oxygen from the atmosphere. Sort of like saying "it's the fall that will kill you". Both scenarios are pretty far off and not deserving of such an alarming headline.

rektide 5y ago

We talk about CO2 all the time but the ongoing combined de-oxygenation and acidification of the oceans & bodies of water seems like such a vastly more real present & immediate threat to me. This article's looking at more radical, longer term shifts. But we are already well well well into the suffocation of the sea. And there's a lot of sea we're suffocating.

jefurii 5y ago

From TFA: "probably won't happen for another billion years or so".

LinuxBender 5y ago

This probably won't happen for another billion years or so. But when the change comes, it's going to happen fairly rapidly, the study from earlier this year suggests. I would really hope that within a billion years we have managed to find other planets, built massive cities or worlds in space especially given the potential collision courses with other galaxies around 1.9 billion years and the expansion of the star we call the sun that will eventually engulf the earth evaporating all the water.

brian-armstrong 5y ago

The abstract has a few more details >>> We find that future deoxygenation is an inevitable consequence of increasing solar fluxes, whereas its precise timing is modulated by the exchange flux of reducing power between the mantle and the ocean–atmosphere–crust system. Our results suggest that the planetary carbonate–silicate cycle will tend to lead to terminally CO2-limited biospheres and rapid atmospheric deoxygenation, emphasizing the need for robust atmospheric biosignatures applicable to weakly oxygenated and anoxic exoplanet atmospheres and highlighting the potential importance of atmospheric organic haze during the terminal stages of planetary habitability.

lholden 5y ago

Not really explained by the linked article, but my understanding is that as the Sun increases in luminosity (increasing the solar flux), the chemical reactions that binds CO2 will increase. Within 500-600 million years the CO2 levels drop beyond the point for C3 photosynthesis. Plants using C4 photosynthesis will survive for about twice as long, though by that point the increased solar flux will have caused the surface temperature on Earth to be uninhabitable anyways. Of course, who really knows how life might evolve to adapt to these changes. Humans have been pretty good at liberating carbon for instance :P.

entropicgravity 5y ago
We should be living on Mars by then and it will have warmed up comfortably.

kaminar 5y ago

Let's just say Bill Gates is already working on it...

K0balt 5y ago

So this implies then that the “Goldilocks”phase of earthlike planets in general may be shorter than thought. It is interesting to me that in the long view, the ability to terraform or colonize space/other worlds turns out to be a survival gate for life forms.

K0balt 5y ago

It would be interesting to see if there is fossil fuel money somewhere behind this article. This is exactly the kind of information that climate change deniers grab onto (“if we run out of co2 we are all doomed! More co2 is better!)