• jol@discuss.tchncs.de
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    2 days ago

    Extinction is highly unlikely. End of civilization perhaps, but humans are extremely hardy and versatile. You would be hard pressed to kill all humans in all biomes.

    • InputZero@lemmy.world
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      2 days ago

      So, aside from the conversation at hand. On a long enough time scale human extinction is inevitable. No species lives forever. Either through evolution or extinction someday there will be a last Homo Sapien Sapien. Perhaps they’ll call themselves Homo Sapien Sapien Sapien.

      • jol@discuss.tchncs.de
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        2 days ago

        The amount of oxygen in the air is hardly changing and would support human life easily after climate change goes bananas. The amount of CO2 that is causing climate change is actually quite tiny even though it doubled or tripled since pre-industrial times. It’s still far less than 0.5% (the safe recommended amount) of the atmosphere. You could triple the current CO2 levels, which would be devastating for the climate, and still breath perfectly fresh air.

      • SoleInvictus@lemmy.blahaj.zone
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        2 days ago

        Luckily, that is extremely unlikely. Even if we were to burn all the fossil fuels on Earth, we wouldn’t even get close. Venus is 42% closer to the sun and has an atmosphere that is about 97% CO2 (compared to Earth’s 0.4%) and a bit over 90 times denser. Fun fact: the atmospheric pressure on the surface of Venus is the same as 900m underwater on Earth. Shit is soupy AF.

        To hit Venus numbers, we’d need a greater than 50% increase in solar luminosity combined with an approximately 2,200,000% increase in atmospheric CO2. That means going from about 3340 gigatonnes of atmospheric CO2 (based on current estimates) to more than 73,000,000 gigatonnes (7.3 × 10¹⁹ tonnes). It’s a staggering increase that is impossible without a massive outside input, like half the earth’s crust splitting open and blasting out CO2.

        Even if we were to substitute methane entirety for CO2, being a 28x more potent greenhouse gas, that still requires an additional 2,600,000 gigatonnes (2.6 × 10¹⁸ tonnes) of methane. Earth’s atmosphere in its entirety is only 5 × 10¹⁵ tonnes.

        • uniquethrowagay@feddit.org
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          2 days ago

          Just a small addition, Earth has a CO2 percentage of about 0.04. We’re not going to be like Venus. But there may still be catastrophic consequences for life as we know it.

      • jol@discuss.tchncs.de
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        2 days ago

        That would probably not happen at a human scale. Civilization would collapse and nature would heal.