Thanks Red Badger.
Posted on 10/15/2021 12:33:25 PM PDT 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, the study from earlier this year suggests.
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 new 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," wrote the researchers in their published 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 new model – 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 earlier this year. "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.
That's a given.
“A Hole C” 🤣
Don’t give a flying fart
In 1 billion years, we will be living on some planet circling Alpha Centauri.
You really are embarrassing yourself.
Of course the air is compressed as it enters the engine, either by the compressor in a turbine engine, or pistons in a reciprocating engine. That air is roughly 20% oxygen - at every altitude.
As the engine altitude increases, the air is less dense, so it contains less oxygen (LESS, not NONE) for a given volume, so less fuel can be mixed with it to get proper combustion, so the engine produces less power ... that’s why your rate-of-climb decreases as your altitude increases.
So I’ve heard.
The list of those who’ve done so does not, and never could have, included me.
You didn’t read the post to me. I answered in a short sentence or two not to get into the engineering of it all; that’s what compressor blades are for and what super chargers are for - never said word one about performance, it was just about fuel combustibility at high altitudes. PERIOD.
From your original Post 15:
“Therefor our oxygen ocean is only 15,000 feet deep.”
I was referring to breathable oxygen - at that altitude you need some help with supplemental O2.
Eventually.🤔
Revert back....aaaarrrrr
We will either:
a. Evolve (or devolve) into something else
b. Colonize space and fragment into other species
c. Become machines
d. Destroy ourselves
e. All of the above
It’s nonsense regardless. In a billion years, we will either be gone or spread out through the galaxy.
Nor me, even at my most fit (which was a long time ago). I’ve worked at about 10,000 feet in Colorado, and there wasn’t nearly enough air in the air. Can’t imagine trying to breathe at nearly three times that altitude.
What nonsense. AOC told us there were only 12 years left.
I think we’re down to about 9?
Oh noes! 😮
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