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Earth

Extreme CO2 Levels Could Trigger Clouds 'Tipping Point' and 8C of Global Warming (carbonbrief.org) 254

If atmospheric CO2 levels exceed 1,200 parts per million (ppm), it could push the Earth's climate over a "tipping point", finds a new study. This would see clouds that shade large part of the oceans start to break up. From a report: According to the new paper published in the journal Nature Geoscience, this could trigger a massive 8C rise in global average temperatures -- in addition to the warming from increased CO2. The only similar example of rapid warming at this magnitude in the Earth's recent history is the Paleo-Eocene Thermal Maximum 55m years ago, when global temperatures increased by 5-8C and drove widespread extinction of species on both the oceans and land.

However, scientists not involved in the research caution that the results are still speculative and that other complicating factors could influence if or when a tipping point is reached. The threshold identified by the researchers -- a 1,200ppm concentration of atmospheric CO2 -- is three times current CO2 concentrations. If fossil fuel use continues to rapidly expand over the remainder of the century, it is possible levels could get that high. The Representative Concentration Pathways 8.5 scenario (RCP8.5), a very high emissions scenario examined by climate scientists, has the Earth's atmosphere reaching around 1,100ppm by the year 2100. But this would require the world to massively expand coal use and eschew any climate mitigation over the rest of this century.
Further reading: A state-of-the-art supercomputer simulation indicates that a feedback loop between global warming and cloud loss can push Earth's climate past a disastrous tipping point in as little as a century.
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Extreme CO2 Levels Could Trigger Clouds 'Tipping Point' and 8C of Global Warming

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  • by Anonymous Coward

    USA could be 100% clean and it won't matter if China and India keep polluting. So this is all fucking pointless.

    • by XXongo ( 3986865 ) on Tuesday February 26, 2019 @10:09AM (#58182440) Homepage

      USA could be 100% clean and it won't matter if China and India keep polluting. So this is all fucking pointless.

      China will, of course, be the country producing those cheap solar panels that will make the U.S. 100% clean, because they manufacture all our cheap stuff.

      Why do you think that they wouldn't themselves use the cheap solar panels they're exporting to us?

      • by es330td ( 964170 )

        Why do you think that they wouldn't themselves use the cheap solar panels they're exporting to us?

        Actually, they do. Because of the size of their population, China's approach to increasing their supply of energy is "all the above."

      • If they can sell them to people in the United States for more than consumers in China would pay, why wouldn't they export them?
      • by Trogre ( 513942 )

        Just because we're outsourcing both our pollution and slavery it doesn't make us immune from their effects.

    • But China is actually already investing heavily in long-term fossil-carbon reduction strategies - they're installing renewable energy generating capacity as fast as the rest of the world combined. They've just decided that they're better off continuing to also use fossil energy in the mid-term to fuel their industrial revolution, and then bear the cost of some modest climate change.

      And of course, their position is that as we're the ones that did most of the existing damage, and we continue to do by far the

  • by LifesABeach ( 234436 ) on Tuesday February 26, 2019 @09:59AM (#58182370) Homepage
    There is an abundance of scientists, but no names; so who the 'f are they?
    • The lead author, Tapio Schnieder, works at California Institute of Technology [climate-dynamics.org]. His email is in the paper (first link on Slashdot) if you want to talk to him, he'd probably respond.
  • by SlaveToTheGrind ( 546262 ) on Tuesday February 26, 2019 @10:10AM (#58182450)

    The publisher made it freely available [nature.com] -- a pleasant rarity.

    Note that the focus of the paper appears to be a possible explanation for extreme temperature changes in the past, not that there's a credible chance of this happening any time in the near future.

  • They are scared of clouds over oceans vanishing? If I u derstood that correctly, doesn't the also mean more water evaporates? And if more evaporates, doesn't that cool thi gs too?

    Not to mention that the water has to go somewhere. Seems to me the climate in Europe is getting dryer. Perhaps that would be impacted as well?

    The whole thing seems a tad too simplified. We're talking about global climate here.

    • The whole thing seems a tad too simplified. We're talking about global climate here.

      Did you read the whole paper before complaining it's a tad too simplified ?

  • by SuperKendall ( 25149 ) on Tuesday February 26, 2019 @10:41AM (#58182622)

    If all of you will think way back to where we first were supposed to be alarmed about global warming, it was exactly because too much CO2 was supposed to lead to runaway warming.

    Well obviously that never happened, and this new paper is admission that fundamental concern was misplaced In fact now we see we need to get to a very high CO2 level we probably cannot even reach, to MAYBE risk a CO2 rise because of cloud interaction (the idea is only theoretical). It's quite apparent at this point that interaction of CO2 with a real world atmosphere is quite a lot more complex than any climate scientist is willing to admit.

    Further proof that what we were told to worry about, should never have been a concern to start with. We seriously need to stop our focus on CO2 and start re-examining real sources of pollution again and focus on those.

    • Well obviously that never happened

      We're not finished yet. CO2 is still being added to atmosphere at increasing rate. First CO2 levels need to stabilize, and then you need to wait a few more decades before you can start claiming that some things will not happen.

      • CO2 is also being taken from the atmosphere by the Earth's ecosystem. It's still a net gain but the trend of overall CO2 emission reduction is very clear, there's no way we will reach the level described even if we did nothing but carried on with existing adoption of solar/nuclear power, and electric vehicles.

        Can you point out any models that show CO2 levels even close to 1200ppm? Even the worst case I can find is 1000ppm by 2100 [www.co2.earth] (still a long, long ways off and more than enough time to fully integrate re

        • Can you point out any models that show CO2 levels even close to 1200ppm?

          No, I was just commenting on the part that I quoted.

          Whether atmosphere will go to 1200 ppm, I have no idea. I can't predict human behavior. Maybe we'll get another world war, crippling economy and energy infrastructure, leading to dramatic drop in output.

          • Whether atmosphere will go to 1200 ppm, I have no idea. I can't predict human behavior.

            You can't? Humans are the most eminently predictable of species, in aggregate.

            Maybe we'll get another world war, crippling economy and energy infrastructure, leading to dramatic drop in output.

            Nope, too much to lose now.

            What I'm saying is that you do not NEED anything like that, even with a great economy in most countries CO2 output is inevitable, precisely BECAUSE of human behavior.

            Electric cars are 100% preferable for

            • by XXongo ( 3986865 )

              Whether atmosphere will go to 1200 ppm, I have no idea. I can't predict human behavior.

              You can't? Humans are the most eminently predictable of species, in aggregate.

              Maybe we'll get another world war, crippling economy and energy infrastructure, leading to dramatic drop in output.

              Nope, too much to lose now.

              That was an argument which was being made before the first world war: there wouldn't be a war, because everybody had too much to lose.

              Turned out to be wrong.

              Wars happen even when both sides lose by having a war.

              • Well bully then, we'll all have a giant war and the resulting millions dead will be much better than the horrors of a slightly warmer Earth with better agricultural production.

    • by XXongo ( 3986865 )

      If all of you will think way back to where we first were supposed to be alarmed about global warming, it was exactly because too much CO2 was supposed to lead to runaway warming.

      I know a lot of atmospheric scientists, and I don't believe I've ever heard one suggest that the current increases in CO2 levels were going to lead to "runaway warming". I've heard quite a few, on the other hand, make the specific point that we are not close to a runaway greenhouse effect, at least, not for the next few hundred million years.

      So: show a citation if you're going to claim this.

      • I know a lot of atmospheric scientists, and I don't believe I've ever heard one suggest that the current increases in CO2 levels were going to lead to "runaway warming"

        Maybe check Google before you post? [google.com]

        Results include such notables as Steven Hawkins:

        ""We are close to the tipping point, where global warming becomes irreversible. Trump's action could push the Earth over the brink, to become like Venus," - SH

        MIT Technology review chimes in with another climatologist saying it could happen.

        How dare you try to

        • by XXongo ( 3986865 )
          ??

          I looked at that google link. It gave a whole page of links saying that we won't experience a runaway greenhouse effect.

          Good to know.

          Here's Scientific American (from the google links you gave) https://www.scientificamerican... [scientificamerican.com]
          [a runaway greenhouse effect would require]: "about 10 times more carbon dioxide than most experts estimate could be released from burning all available fossil fuels."

          Here's that Technology Review article you mention: "almost all lines of evidence lead us to believe that it is u

  • by Zorro ( 15797 ) on Tuesday February 26, 2019 @10:53AM (#58182690)

    Triassic: 1750 ppm CO2. Temp 3 C above modern level.
    Jurassic: 1950 ppm CO2. Temp 3 C above modern level.
    Cretaceous: 1700 ppm CO2. Temp 4 C above modern level.
    Paleogene: 500 ppm CO2. Temp 4 C above modern level.
    Neogene: 280 ppm CO2. Temp 0 C above modern level.
    Quaternary Period: 250 ppm CO2. Temp 0 C above modern level.

    Then you get to the Modern Period. Frankly we are still living in an Ice Age.

    • You ignore the fact that the Sun was about 30% dimmer at the beginning of Earth's history, and has slowly increased to current power.

      • Re: (Score:3, Insightful)

        by Anonymous Coward

        Bullshit responses like that are why people become climate skeptics. Solar output was not 30% lower in any of the periods that OP showed. Solar output was much lower when the earth formed but was constant through all of those periods. So are you telling half truths through ignorance? Or are you deliberately trying to obscure the truth?

      • by Trogre ( 513942 )

        True, but not really relevant [wikipedia.org] when discussing a couple of hundred million years.

  • But wait! If higher CO2 eliminates clouds, why does Venus (which has an extremely CO2-rich atmosphere) also have about 100 percent cloud cover?!?

    • The clouds on Venus are not water but sulfuric acid.

    • by XXongo ( 3986865 )
      The results being discussed are not about "clouds" generically, but about a particular kind of cloud, high stratospheric clouds.

      The thick cloud deck on Venus is much lower than equivalent altitudes to the stratosphere.

      (and, in any case, they are H2SO4 clouds, not water ice clouds. Different properties.)

  • I would like there to be serious consequences for these prediction not panning out. So far very, very few models have shown any predictive power, and they're all on the "less dramatic", non-doomsday side of the spectrum. So I'd like to see real consequences for alarmism. I.e. we record the prediction, and then 20 years later if it's within less than, say 20% accurate, and it was used to influence public policy, you get to pay 1% of the cost of the measures taken or something like that. I'm open to suggestio

    • I would like there to be serious consequences for these prediction not panning out.

      Does that include the null predictions that nothing is going to happen ?

      • by melted ( 227442 )

        Sure, you can include that. But since no money is spent if "nothing is going to happen", the consequences are also null.

        • since no money is spent if "nothing is going to happen", the consequences are also null.

          Right, waiting and doing nothing is free. Dealing with the consequences is not. If you predict there will be no sea level rise, you will pay 1% of the cost associated with flooding due to higher sea levels, for example.

  • This is a modification of a previous post. It's all well and good for researchers to think about climate change. To me, it's pretty clear that climate science has the general picture right, even if individual models are all imperfect.

    However, I doubt anything serious will be done until it becomes a *real* and *immediate* problem that's undeniable to *most* of the planet. In the past, humanity was able to do things proactively, like agree to limit fluorocarbons to fix the hole we punched in our ozone la
  • Global avg surface temp is 15 deg C (14.9) that gives us a water vapor pressure of 12.8 torr

    According to http://www.wiredchemist.com/ch... [wiredchemist.com] ..if we increase temps by 8C that raises that to 21 torr.

    I rather expect that increasing the vapor pressure of water by 64% will increase cloud formation substantially?

    • by XXongo ( 3986865 )
      The particular study being discussed was not about "clouds" generically, but specifically about a particular kind of cloud, high stratospheric clouds.

      Low clouds act differently from high clouds. (Among other things, they tend to be liquid water droplets, not ice particles.)

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