The future lifespan of Earth’s oxygenated atmosphere

Re:The future lifespan of Earth’s oxygenated atmosphere by taylodl on Wednesday March 03, 2021 @09:11AM (#26328485)

As I understand it the sun has another 4.5 billion or so years of life remaining but the earth has only another billion years or so of being habitable. That's interesting. Complex life first appeared on earth about 2.5 billion years or so ago and has 1 billion more years to go for a total span of 3.5 billion years. In earth's projected 9 billion year lifespan it will only have been habitable for 3.5 billion years, or 39% of that time. A technologically advanced civilization will have only existed for 1 billion years - or 11% of that time (that's assuming of course some form of advanced civilization continues on earth for another billion years).

Those are interesting numbers to consider when searching for extraterrestrial life in other planetary systems: 39% of planetary lifespan had advanced life, 11% of planetary lifespan had technologically advanced civilization.

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Re:The future lifespan of Earth’s oxygenated atmosphere by derekp7 on Wednesday March 03, 2021 @09:53AM (#26329075)

Is there enough selective pressure to keep human-style intelligence in the gene pool for another billion years? Look at the abundance of species on Earth, and only one species has a space program. Is there enough selective pressure for other species to eventually evolve advanced intelligence (considering how much of it that crows and dolphins have) or is it just an accident that humans have it, and it may not stay in our genes forever?

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Re:The future lifespan of Earth’s oxygenated atmosphere by ben_w on Wednesday March 03, 2021 @10:35AM (#26329701)

That question is definitely unknowable in advance, because our intelligence level leads to radical changes in the environment in which we exist.

If we really, really, cared, we could set up a momentum exchange between Earth and Jupiter mediated by an asteroid, moving Earth further out and Jupiter (slightly) further in, chasing the outward drift of the Sol habitable zone: https://arxiv.org/abs/astro-ph/0102126

Also, we could (in principle, not saying we will or we should) engage in selective breeding or genetic engineering of ourselves; and while mind-uploading is currently SciFi, it’s in the category of “we recon this is eventually possible” rather than “convenient plot device”.

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Re:The future lifespan of Earth’s oxygenated atmosphere by Supermancho on Wednesday March 03, 2021 @10:41AM (#26329792)

If you want to expand semi human traits to other planets (anywhere) you will need genetic engineering. Full stop. The idea that humans can be transplanted as-is does not hold given the results on the home planet.

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Re:The future lifespan of Earth’s oxygenated atmosphere by ben_w on Wednesday March 03, 2021 @10:46AM (#26329882)

OTOH, O’Neill cylinders are an alternative instead of planets, while the bad previous experiences with eugenics (and the tendency people have towards appeal-to-nature fallacy) may make people actively reject GM humans.

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Re:The future lifespan of Earth’s oxygenated atmosphere by ido on Wednesday March 03, 2021 @10:06AM (#26329260)

Evolution takes a very long time. If we manage to not kill our own civilisation we will be fine as our technology will advance many orders of magnitude faster than evolution will be able to cause any significant changes to our intelligence via natural selection.

Anatomically modern humans evolved 300k years ago and didn't change much since. Can you imagine what kind of progress we will make in the next 300k years? I can't even imagine the next 1000 years.

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Re:The future lifespan of Earth’s oxygenated atmosphere by taylodl on Wednesday March 03, 2021 @10:28AM (#26329573)

That's a fascinating question! First, it raises the idea that human intelligence may actually decrease over time, especially as we offload our thinking to machines. It's hard to tell whether that will increase or decrease our intelligence or leave it roughly the same. I have a hunch, and it's just a hunch, that our intelligence will increase over time.

With regards to dolphins and crows - wow! What a find animals like that would be on another planet! Quite intelligent - but not technologically advanced. You raise an interesting question: assuming a planet has evolved life having the intelligence of a crow or dolphin, what's the probability that planet will evolve a technologically advanced life form? How likely is it earth is the only planet to have evolved such a life form?

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