Posted on 12/08/2022 8:42:09 AM PST by Red Badger
For now, life is flourishing on our oxygen-rich planet, but Earth wasn't always that way – and scientists have predicted that, in the future, the atmosphere will revert back to one that's rich in methane and low in oxygen.
This probably won't happen for another billion years or so. But when the change comes, it's going to happen fairly rapidly, according to research published in 2021.
This shift will take the planet back to something like the state it was in before what's known as the Great Oxidation Event (GOE) around 2.4 billion years ago.
What's more, the researchers behind the study say that atmospheric oxygen is unlikely to be a permanent feature of habitable worlds in general, which has implications for our efforts to detect signs of life further out in the Universe.
"The model projects that a deoxygenation of the atmosphere, with atmospheric O2 dropping sharply to levels reminiscent of the Archaean Earth, will most probably be triggered before the inception of moist greenhouse conditions in Earth's climate system and before the extensive loss of surface water from the atmosphere," the researchers explained in their paper.
At that point it'll be the end of the road for human beings and most other life forms that rely on oxygen to get through the day, so let's hope we figure out how to get off the planet at some point within the next billion years.
To reach their conclusions, the researchers ran detailed models of Earth's biosphere, factoring in changes in the brightness of the Sun and the corresponding drop in carbon dioxide levels, as the gas gets broken down by increasing levels of heat. Less carbon dioxide means fewer photosynthesizing organisms such as plants, which would result in less oxygen.
Scientists have previously predicted that increased radiation from the Sun would wipe ocean waters off the face of our planet within about 2 billion years, but the model here – based on an average of just under 400,000 simulations – says the reduction in oxygen is going to kill off life first.
"The drop in oxygen is very, very extreme," Earth scientist Chris Reinhard, from the Georgia Institute of Technology, told New Scientist. "We're talking around a million times less oxygen than there is today."
What makes the study particularly relevant to the present day is our search for habitable planets outside of the Solar System.
Increasingly powerful telescopes are coming online, and scientists want to be able to know what they should be looking for in the reams of data these instruments are collecting.
It's possible that we need to be hunting for other biosignatures besides oxygen to have the best chance of spotting life, the researchers say. Their study is part of the NASA NExSS (Nexus for Exoplanet System Science) project, which is investigating the habitability of planets other than our own.
According to the calculations run by Reinhard and environmental scientist Kazumi Ozaki, from Toho University in Japan, the oxygen-rich habitable history of Earth could end up lasting for just 20-30 percent of the planet's lifespan as a whole – and microbial life will carry on existing long after we are gone.
"The atmosphere after the great deoxygenation is characterized by an elevated methane, low-levels of CO2, and no ozone layer," said Ozaki.
"The Earth system will probably be a world of anaerobic life forms."
The research has been published in Nature Geoscience.
A version of this article was first published in March 2021.
So we just need a sustainable population of humans who constantly replenish carbon back into the atmosphere? Basically just keep driving cars etc at a rate the earth can renew carbon deposits.
In other words to be conservative and not use it all up as a fast as possible.
An air tax might work.
“They’re so stupid, they think they’re smart.”
1 Corinthians 3:19
For the wisdom of this world is foolishness before God. For it is written, “He is the one who catches the wise in their craftiness”;
Job 12:24
“He deprives of intelligence the chiefs of the earth’s people
And makes them wander in a pathless waste.
"Excuse me, professor. But didn't you just say that more carbon dioxide means fewer photosynthesizing organisms such as plants, which would result in less oxygen?"
"Yes. What is your point?"
Flourine is an even more reactive element . Try finding that outside of a compound.
A billion here, a billion there, and pretty soon your talking about real time...................
We have spider plants all over the place!................
This probably won’t happen for another billion years or so.
—
I’ll pencil it in on my calendar.
Words of wisdom from my dad... “If they could figure out a way to tax the air we breathe, they would.”
Not my monkey, not my problem.
Pretty sure before that happens we are gonna get hit by an asteroid or other great Ctr/Alt/Del ELE and this whole fairy-tale will come to a screeching halt anyways...
Thanks Red Badger. A large impact will sanitize the planet long before that, and impact is likely the only mechanism that could/would/can/will remove all the oxygen.
I'm not too impressed with the Human Condition anymore but if we are still around in a billion years 'or so' I think we can figure this one out.
Cutting it by 2/3 would do it...
Man will off himself before then.
Weer doomed.
My father was in his chemistry class when the professor was caught it a paradox. She first claimed there is no universal solvent. A few minutes later, discussion of hydrofluoric acid as a means of dissolving metallic gold was raised. She said it was very difficult to handle because it can dissolve anything. My dad raised his hand. His question? Doesn't that make it a universal solvent? The prof was flustered and couldn't find a reasonable explanation of the paradox.
In practice, you need a mix of hydrochloric and hydrofluoric acid to successfully dissolve gold. In the electron microscopy lab, I used a gold nitrate stain on my rat liver "silver sections". Clearly, the metallic gold had to be dissolved to create a nitrate salt.
In the Year 2525.................
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