The future lifespan of Earth’s oxygenated atmosphere

https://www.nature.com/articles/s41561-021-00693-5#data-availability

by Guardianmag • 5 years ago

54 84 5 years ago

nature.com

gspr• 5 years ago

This is one can I'm OK with kicking down the road :-)

(I'm joking; the article is interesting, and I'm not trying to frame it as trying to portray this as an urgent threat)

tzs2• 5 years ago

Definitely a kick it down the road problem.

It's one of a whole class of problems that (1) we will have to solve or we will go extinct, but (2) are completely and utterly pointless to actually try to solve now because they are so far beyond our level.

When some far future people finally have the ability to seriously start working on one of these problems, they will have techniques and knowledge so far ahead of us that anything our best and brightest could do in a lifetime's work now on the problem will be something the future people can trivially do in a day.

The only contribution we can make now to these problems is to just continue to improve our science and engineering in general, in the hope that if we do that for enough generations then eventually our successors will have enough accumulated knowledge to actually tackle these problems.

enkid• 5 years ago

"Only"

Causality1• 5 years ago

Patently ridiculous to make the assumption that given a billion years, no multicellular photosynthesizing organisms will adapt to the changing environment. A billion years.

echelon• 5 years ago

Oxygen is a best in class reagent. Lots of pent up energy. You're correct that it's not necessary, but it's going to be tough without it.

devops000• 5 years ago

Enough time to migrate to another planet.

vimacs22• 5 years ago

It's literally enough time to even lift heavier elements from the Sun to extend it's stable life cycle by several billion years.

Another commenter suggested moving the planet and got down voted to oblivion but it's not at all a ridiculous suggestion in these kinds of time scales. You could place giant ion thrusters on the moon and set it in an orbit where tidal effects would nudge the Earth outwards over a few million years. This can be made subtle enough as to not even be noticeable to life on Earth.

Of course a cheaper solution is to just use a solar shade that can incrementally decrease it's opacity to compensate for the brightening sun but this would not be enough when the Sun transitions into it's red giant phase

AnIdiotOnTheNet2• 5 years ago

The problem isn't the engineering, as usual, it's political. Can you realistically foresee humanity taking on such long term projects? We can't even get people to stop burning fossil fuels to "mine" cryptocurrency.

grumple• 5 years ago

I can't see the paper [1].

But the code is here: https://github.com/kazumi-ozaki/lifespan/blob/master/main.f9...

It does not give me great confidence in the modeling. Perhaps the paper goes into great detail about the formulas used in the code, and explains those variables and naming choices (those not in the Constants file with comments), or the fitting coefficients.

Of course, I really wonder how the complexity of the natural world could be captured by a few hundred variables.

1. https://www.nature.com/articles/s41561-021-00693-5#data-avai...

adolph• 5 years ago

Complexity from Simplicity

https://science.sciencemag.org/content/340/6134/822.full

egberts2• 5 years ago

The sky is falling... The sky is falling...

Get to work on those planet hunting.

ben_w3• 5 years ago

Some of it is falling, some of it is boiling off into space.

hackeraccount• 5 years ago

My impression is that a large amount of what we think as non-biological is in fact the product of life. Making the prediction that life will be unable keep the environment the same despite external factors seems like a bold predication; let's see how it plays out.

josemanuel• 5 years ago

Earth will not host complex plants in 600 million years. So that’s also a problem - https://en.m.wikipedia.org/wiki/Timeline_of_the_far_future

domano• 5 years ago

Thanks for the link, these really long term timelines always trigger a perspective shift for me.

simonebrunozzi• 5 years ago

Please post non-mobile links to wikipedia when you can [0]

[0] https://en.wikipedia.org/wiki/Timeline_of_the_far_future

wsinks• 5 years ago

Serious question, why?

If you're on a phone, does the non-mobile link redirect to mobile?

The formatting on the mobile site looked just fine to me on a laptop. I'm sure there's a good reason I'm missing.

earthling51• 5 years ago

Separating presentation by subdomain feels like a relic from the 2000s or earlier. Wikipedia is one site that could do to be modernised with dynamic formatting or whatever it's called. Even BBC moved news.bbc.co.uk to bbc.co.uk/news although that is not quite the same thing.

aaomidi• 5 years ago

Wikipedia should auto redirect to non mobile site when you're not on mobile. Requiring people to follow unwritten rules is annoying.

Why is Wikipedia not doing this?

tablespoon2• 5 years ago

Earth will not host complex plants in 600 million years. So that’s also a problem - https://en.m.wikipedia.org/wiki/Timeline_of_the_far_future

If I'm reading that right, that's only C3 plants. C4 plants would keep going until 800–900 million years. And who knows if something else doesn't evolve or is engineered for the different conditions.

goatlover• 5 years ago

Time enough to terraform Venus.

yxhuvud• 5 years ago

Eh, if the Sun is too hot for Earth, what makes you think Venus would be better?

epx• 5 years ago

We will have built a Dyson sphere to mine Bitcoin until then.

AnIdiotOnTheNet2• 5 years ago

There some potential here for a hilarious short story about earthlings trying to convince aliens to accept Bitcoin after doing that.

excerionsforte• 5 years ago

I wonder if the great filter is not one, but multiple coincidences brought upon by "intelligent" life and the natural lifetime of a planet and/or solar system.

If Mars had intelligent life and now it doesn't how does that bode for Earthlings? Can life really adapt given the lack of evidence anywhere?

I wonder how will space travel to the next possible habitable planets work. Shoot in all directions and hope that life spawns on a few of those possible habitable planets that are light years away.

Robotbeat8• 5 years ago

I think we can all but rule out a dead, ancient planet-spanning civilization on Mars now. We have medium resolution imagery of the entire planet and high resolution (meter or submeter) imagery of a lot of the surface, in a wide distribution. Mars hasn’t had enough volcanic activity to hide evidence of a planet-spanning civilization unless it occurred while large asteroid impacts were much more common.

Venus, however, is sheathed in clouds. So we only have low resolution radar images of most of the planet, and we’ve only sent a few very short-lived landers with low resolution cameras to the surface. They could have landed in areas that were once oceans or otherwise uninhabited. And secondly, Venus has been basically completely resurfaced with lava over time. Venus may once have had large oceans before runaway greenhouse effect. (And keep in mind that the Sun has gotten significantly brighter over billions of years, besides the increased greenhouse effect on Venus.) And so we can’t even rule out a planet-spanning civilization like our own. It’d take a lot more exploration and drilling to rule that out.

derekp73• 5 years ago

I always wondered what it would be like if Mars and Venus were swapped. Would Mars be warmer, or would it be even more devoid of atmosphere? And would Venus (with its greenhouse gas) be a more livable temperature if it was in Mars's orbit? It still wouldn't be survivable due to the atmospheric composition, but I was just wondering about raw climate.

Communitivity2• 5 years ago

A planet spanning civilization on Mars is less likely. However, there are still ways it could be found, depending on how long ago it was. I list three ways below, and suspect there are more.

First, there is the possibility of a civilization dying and evidence being erased by tectonic plate recycling. Mars is approximately 4.6 billion years old. We know it has volcanic activity, and most consider it to have inactive tectonics now. Some scientists believe it could have had significant activity in the past, based on the 3 distinct regions of Mars. Earth's tectonic plates vary in their rates of recycling: the oldest non-oceanic tectonic plate is 3.6 billion years old, and shows no sign of recycling. Oceanic plates recycle on the average of every 180 million years though.

Second, there is the possibility of technology that didn't leave a visible trace. This is not supported by any evidence and is mere conjecture. If the society tore down non-organic structures and converted to using all biodegradable/organic materials then evidence of the society would be scarce, if existent at all, especially if bodies were cremated as many do today. Chemical analysis could detect this I suspect, or more importantly prove it wrong.

Last, if for some reason civilization evolved underground and stayed underground, then there wouldn't be any visible evidence above ground. This is also pure conjecture. Micro-robots that explore Mars' caves might find something, as might ground penetrating radar.

Robotbeat8• 5 years ago

As far as your latter point about life spreading, what’s interesting to me is that the most strict interpretation of our “planetary protection” guidelines at NASA actually prohibit life spreading to other worlds.

Red Tape as the real Great Filter...

Communitivity2• 5 years ago

It would not surprise me if civilizations evolved in the same way life did on Earth.

Life evolved in the sea. At some point life evolved to leave the sea and go to land, whether the sea was no longer hospitable enough, or in search of better food. Life continued to evolve on Land, specializing into different groups and colonizing different lands.

Perhaps civilizations evolve on their planet, then at some point they leave their planet and go into space (when their planet is no longer hospitable or they need more/better food). Finally, while in space they evolve more, founding different colonies that evolve differently due to culture and environmental differences.

richardfey2• 5 years ago

This sounds like a lot of wishful thinking.

The most probable scenario is that life is born multiple times, in multiple places, when conditions permit it.

There's no evidence of life moving across planets of different star systems.

superbcarrot• 5 years ago

We also won't have oceans by then - https://en.wikipedia.org/wiki/Future_of_Earth

And it's very hard to conceptualise what a billion of years in the future actually means.

einpoklum• 5 years ago

TL;DR: It's basically just than speculation based on the sun being hotter in a Billion years.

So, two people ran one model described in one paper. Even if that was the whole issue, it would merit "may last only" rather than "will last only".

Additionally, the authors are making a variety of assumptions with little or no basis about the behavior and development of Earth Flora and Fauna; specifically, that it will be mostly static in most ways, with no adaptation in genetics, inter-species interaction, prevalence in different places on Earth etc.

Having said that - in 5 Billion years, Sol will become a Red Giant, so this planet is going South at some point between now and then.

dwheeler• 5 years ago

That's an incredibly long time, and there's no reason to assume our technology can't get better in that time (if we are around). Another solution is to move spaceship Earth: https://dwheeler.com/essays/move-spaceship-earth.html

JackFr2• 5 years ago

Makes me think of http://www.infinityplus.co.uk/stories/england.htm

taylodl2• 5 years ago

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.

derekp73• 5 years ago

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?

ido• 5 years ago

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.

taylodl2• 5 years ago

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?

ben_w3• 5 years ago

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”.

platty• 5 years ago

Dang, I just moved into a new apartment too

tabtab3• 5 years ago

Here's a real-estate tip: when the sun bloats up into a red giant, Uranus will be a hoppin' joint with spiffy weather. I just hope they change the name by then.

sebringj3• 5 years ago

We humans will be able to control everything on earth's climate if we survive even a couple thousand years from now assuming technological advances.

jacquesm• 5 years ago

What makes you think that?

sebringj3• 5 years ago

The pace of current technology seems like it is speeding up more and more. Feels like a solid prediction even in hundreds of years of not thousands but of course if there is no civilization-ending thing that happens.

JackFr2• 5 years ago

assuming technological advances.

Kind of makes it a tautology.

sebringj3• 5 years ago

I think the point was a billion years is quite a long time and many things we know today will not be the same. Predictions were made about the amount of horse dung that will overrun new york city if the pace of traffic continues, as an example.

istjohn4• 5 years ago

I can imagine a scenario where civilization collapses and humankind exists in a permanent dark age without abundant oil to launch a new industrial revolution.

Edit: Another alternative is technology progresses but political and cultural institutions do not, so the requisite level of global cooperation never materializes.

istjohn4• 5 years ago

Interesting. Life emerged 4 billion years ago and the window of habitability for complex lifeforms will end in one more billion years. So terrestrial natural selection required 80% of the window of opprtunity to produce human intelligence. That's a tighter margin than I would have guessed.

DavidSJ3• 5 years ago

This is predicted by the hypothesis that the origin of intelligent life requires the occurrence of several hard steps, each of which take at least several billion years (but with no upper bound) in expectation.

If that hypothesis holds, then conditional on all the steps having completed on a given planet, they will have done so roughly equally spaced in the time allotted, regardless of their relative difficulty.

So, for example, if the window on Earth is 5 billion years, and there are four hard steps to complete, then, conditional on all four steps finishing, we expect each step to have taken about 1 billion years, give or take, with about 1 billion years left to go.

(See the Technical Appendix to Robin Hanson's Great Filter essay: http://mason.gmu.edu/~rhanson/greatfilter.html#appendix, or his more detailed discussion of this particular point: http://mason.gmu.edu/~rhanson/HARDSTEP.PS)

istjohn4• 5 years ago

Why do we think the origin of intelligent life requires a few hard steps and not just a continuous progression or perhaps one hard step and otherwise a steady progression?

lenkite• 5 years ago

So basically there is only a limited window for life to kickstart from microbes to multi-cellular lifeforms to sapient beings and finally to spacefaring, terraforming civilisations.

piokoch• 5 years ago

I am not getting this kind of journalism. Guardianmag magazine article is a direct copy paste from https://phys.org/news/2021-03-simulations-earth-oxygen-rich-.... Yes, they cite that as a source (oddly enough, Guardianmag has not added web site address as a clickable link, why?). They didn't have any incentives to add some more details, anything, just copy paste.

It would be so great to learn some more details about the model, etc.

vcdimension2• 5 years ago

That article really doesn't give a very good explanation at all, it doesn't make sense. When CO2 breaks down it produces oxygen and carbon, so if oxygen gets burned to produce CO2 it's just gonna get converted back into oxygen when the CO2 breaks down. If the oxygen reacts with the atmospheric nitrogen then surely this will also get broken down since AFAIK less energy is needed to break down NO2 than CO2. Currently the amount of oxygen in the atmosphere is over 500x more than the amount of CO2, so where is all that oxygen going to go?

Robotbeat8• 5 years ago

There’s an immense amount of buried carbon. If you include all burnable carbon sources underground (including under the oceans), there’s approximately enough to burn up all the oxygen in the atmosphere. Plus there are lots of minerals that can be oxidized.

vcdimension2• 5 years ago

burning carbon creates CO2, which would then get broken down back into oxygen (either by plants or directly by sunlight according to the article).

amelius• 5 years ago

Funny, I just posted this 2 days ago:

https://news.ycombinator.com/item?id=26296596

woeirua• 5 years ago

Life on Earth already survived one transition from an anoxic environment to an oxygen-rich environment, I see no reason to expect that it could not make the transition back to an anoxic environment. Granted it may not look anything like the life we're accustomed to today, but I suspect life will exist on Earth in some way, shape, or form for a long time to come.

tabtab3• 5 years ago

For simple life-forms, perhaps, but complex life probably requires rather special or rare circumstances. In areas of Earth low in oxygen, the life-forms there are similar to ediacaran fauna: slow and soft. Increases in oxygen are probably a key cause of the Cambrian explosion.

Perhaps it's possible there is another high-metabolism cycle that doesn't involve much oxygen, but nobody really knows both if a pathway exists, and if evolution can "find" it in time. Any biochemists here who want to weigh in?

imwillofficial• 5 years ago

I find articles like this rich. We don't even know by what mechanism the medication I take every day works, yet people think they can confidently postulate on far distant and far future events with any kind of certainty.

egberts2• 5 years ago

Just move the Earth to a new orbit. In a billion year, our terraforming technology will advance enough for us post-humanoid species to do complex orbital adjustments. — Problem solved.

rory• 5 years ago

Lord Ruler!

d--b• 5 years ago

In all candidness: can someone tell me what the point of these studies is?

macintux• 5 years ago

Completely uninformed speculation:

* Provide more information to the search for habitable planets/extra-solar life

* Better understand how the Earth's atmosphere and overall ecosystem evolves over time, which may inform our understanding of long-term risks of climate change (and perhaps contribute to our ideas of how to manage terraforming on Earth, if we need to mitigate climate change).

richardfey2• 5 years ago

They provide the fortran code too! Sweet

https://github.com/kazumi-ozaki/lifespan

watertom• 5 years ago

Phytoplankton is responsible for 50-80% of all oxygen in the atmosphere. The World wide phytoplankton population has been in decline since the 50’s, down almost 40%. As the population continues to decline it will hit a tipping point and the population will crash, when that happens, we’ll get to witness what happens when oxygen levels decline.

tabtab3• 5 years ago

The sun and humanity are in a brutal contest over who can bleep up life on Earth first. So far the humans are ahead.

tzs2• 5 years ago

PBS Space Time had a nice episode on the timeline to uninhabitable Earth [1].

[1] https://www.pbs.org/video/the-end-of-the-habitable-zone-4t8g...

The future lifespan of Earth’s oxygenated atmosphere

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