The Great Oxygenation Event

https://bigthink.com/starts-with-a-bang/oxygen-killed-life-on-earth/

by Brajeshwar • 2 years ago

115 42 2 years ago

I wish more people were aware of this.

It's helpful to recognize that we're not the first organism to risk undermining the conditions that made us successful by altering the gas mixture in the atmosphere, and that 400 million years of ice is the sort of consequence that we're playing with.

silverquiet• 2 years ago

I used to be optimistic that we had a bit more agency than bacteria, but so far we do not seem any more able to constrain ourselves.

01HNNWZ0MV43FF• 2 years ago

Coordination is hard :/

48864w6ui2• 2 years ago

By population, bacteria are fitter than we are

deepsun• 2 years ago

But we're not going to get another 400m years, because the Sun grows hotter. In 500m years all the oceans will boil.

pixl97• 2 years ago

I mean, if we actually last another 400m years, or even 1 million it's completely possibly that we could slowly shade the Earth with solar shades orbiting the planet. It does not take 'much' energy to reduce the energy input to the planet when you can move things on very long timescales.

angiosperm4• 2 years ago

With any luck, it will happen in just a few centuries as waste heat from industrial processes grows without bound, unless industrial expansion moves off-world before then.

Lyngbakr• 2 years ago

If you're interested in even more on the subject, Don Canfield wrote an enjoyable deep dive on oxygen's history.†

† https://press.princeton.edu/books/hardcover/9780691145020/ox...

JohnMakin• 2 years ago

Always puzzles me when looking for evidence of extraterrestrial life on exoplanets we always try to look for oxygen - life existed for a long time without it

svachalek• 2 years ago

Detecting that a planet might barely support life is impossible to do remotely for our next door neighbor Mars, and we have rovers and orbiters sending high resolution images every day. For exoplanets, we're working with 1 pixel images. Not 1 megapixel, 1 pixel. So for now we can only look for things that would make scientists say whoa, how can that possibly happen?

passwordoops2• 2 years ago

I wouldn't say the planet "barely" supported life before the oxygenation event. Otherwise we wouldn't have as much fossil evidence as we have.

I'd rephrase what you wrote with our current technical limitations make it more feasible to detect life by finding something that would make astrobiologists say woah, how can that possibly happen?

ordu• 2 years ago

A policeman sees a drunk man searching for something under a streetlight and asks what the drunk has lost. He says he lost his keys and they both look under the streetlight together. After a few minutes the policeman asks if he is sure he lost them here, and the drunk replies, no, and that he lost them in the park. The policeman asks why he is searching here, and the drunk replies, "this is where the light is".[1]

Science very thoroughly follows the drunkard principle, because there is no sense in looking at places were you unable to find anything. Science is looking for what it can possible see. It cannot see a bacteria under ice of Enceladus, so it doesn't even try. But it can see sometimes gases around Enceladus, so it looks for them.

https://en.wikipedia.org/wiki/Streetlight_effect

gizmo686• 2 years ago

We don't just look for oxygen. For instance, there was some excitement a few years back when there was a tentative observation of phosphine in Venus's atmosphere.

To have a good biosignature, you want a signal that cannot be explained by anything other than life. Of course, that means that there might be planets with life that we do not notice, because all of the observables we have access to have an abiotic explanation. Not much you can do about that other than a bunch of science.

renewiltord• 2 years ago

Becomes easier to understand when you design a different search and estimate cost. Try it.

teekert• 2 years ago

Relevant to this, on Netflix: Life on our Planet. Highly recommended. Have watched it 3 times with my son now.

RosanaAnaDana• 2 years ago

Really, really weird that the article doesn't even mention nitrogen, nostoc or heterocysts. I'm not sure you can have a conversation about the great oxygen holocaust without at least bringing up one of the primary reasons we know "something" about the conditions before the event, specifically that there are still bacteria around today who are putting out a pretty significant amount of effort to create anoxygenic environments specifically for nitrogen fixation; that nitrogen as a terminal electron receptor basically 'cant happen' in the presence of oxygen.

Its just weird to not discuss the evolutionary lineage that still uses pre-oxygenation event hardware (with some extreme bug fixes to deal with oxygen) to fix nitrogen.

falserum4• 2 years ago

Informative

emjoes1• 2 years ago

What is the great oxygen holocaust? Odd choice of words.

angiosperm4• 2 years ago

99%+ of species were driven to extinction, first from their environments becoming bathed in oxygen they were powerless to resist, and then from the whole planet freezing over for an eon (except maybe some equatorial refugia). Volcanism eventually restored enough CO2, with the oxygenators frozen, so the ice could melt.

angiosperm4• 2 years ago

Are these the bacteria that literally all other life on earth depend on to split N2 so they will be able make protein and reproduce?

zamalek• 2 years ago

Could we not employ the same cyanobacteria to avert our current Great Deoxygenation Event? It did consume CO2 after all?

dimitar• 2 years ago

The Great Oxygenation event wasn't due to the consumption of CO2 but rather the reaction of methane with the newly introduced oxygen, which reduced the greenhouse effect (aka raditative forcing). Since we already have lots of oxygen in the atmosphere they cannot help us the same way.

voldacar• 2 years ago

Why is this flagged?

48864w6ui2• 2 years ago

Maybe someone on a phone meant to click hide?

superasn• 2 years ago

relevant: https://news.ycombinator.com/item?id=30253799

hackeraccount• 2 years ago

Isn't there a Larry Niven story about some pre-oxygination civilization on earth? The Green Plague I think.

The Great Oxygenation Event

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