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Science

Major Study Rules Out Super-High and Low Climate Sensitivity To CO2 (arstechnica.com) 140

Scott K. Johnson writes via Ars Technica: One of the most important numbers in climate science is 3C. This isn't about a projection of future warming or the impacts that come with it, though. It's about how much warming you get if you double the amount of greenhouse gasses in the atmosphere. That value can be made more general as a metric known as "climate sensitivity," which describes how much warming you get for a given amount of emissions. If the number is small, we can burn a lot of fossil fuels with minimal consequences. If the number is extremely high, emissions are extraordinarily dangerous. This number is commonly defined against a doubling of the concentration of CO2 in the air, in part because CO2's effect is logarithmic and each doubling is roughly equivalent. Calculations of this value go back to the turn of the 20th century, when the Swedish scientist Svante Arrhenius came up with numbers in the 4-6C range. But a major milestone was reached in 1979, when a group of scientists released a climate report that included this value. The scientists wrote, "We estimate the most probable global warming for a doubling of CO2 to be near 3C with a probable error of +/-1.5C."

Despite all the scientific progress since then, that answer (1.5-4.5ÂC) has held up. The 2007 Intergovernmental Panel on Climate Change report tightened it up a bit to 2.0-4.5C, but then a handful of studies released just before their 2013 report caused confusion that led to a return to the old 1.5-4.5C range. Shrinking that range has been a goal of climate scientists, though the problem has proved stubborn. In a notable step forward, a group of 25 climate scientists published a study this week that presents a new synthesis of the evidence. And they conclude that a narrower range is warranted.

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Major Study Rules Out Super-High and Low Climate Sensitivity To CO2

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  • 0.55 C (Score:2, Interesting)

    The climate alarmists believe the climate warms directly by 1.1 C per doubling of CO2 concentration and that an indirect feedback multiplier of 3x gets applied to this warming. The climate skeptics believe that the climate warms directly by 1.1 C per doubling of CO2 concentration and that an indirect feedback multiplier of 0.5x gets applied to this warming. Even intuitively, if the feedback multiplier were >= 1, the climate would have run away billions of years ago. The skeptic model matches observed
    • Re: (Score:2, Troll)

      Comment removed based on user account deletion
      • That is nonsense.
        See: https://www.scientificamerican... [scientificamerican.com]
        "Most of these models are long since obsolete, replaced by far more advanced generations. And yet, most of them were spot on in their projections of how much the Earth would warm in the years after they were published in response to greenhouse gas emissions. Fourteen out of 17 models were found to be accurate."
        • Take a close look at the model accuracy of those 14 'successful' models. Sure it makes for pretty pictures, but to make them successful they had to give them an acceptable error ratio that makes them not much better than throwing darts at a dart board. Their cumulative gain range is massive, because their precision barely cracks 0.5 Anything below 0.95 is not an accurate model. It is a S.W.A.G at best.
    • by PPH ( 736903 )

      the climate would have run away billions of years ago

      It did. In both directions. We have had much warmer climates, no O2 and lots of CO2, no glaciers and temperate forests in Antarctica and an ice-covered earth. The climate is chaotic and for all we know, just a bit more CO2 and we might trigger the next ice age.

      • by stwrtpj ( 518864 )

        It did. In both directions. We have had much warmer climates, no O2 and lots of CO2, no glaciers and temperate forests in Antarctica and an ice-covered earth. The climate is chaotic and for all we know, just a bit more CO2 and we might trigger the next ice age.

        One thing that tends to get ignored in scenarios like this is the amount of time that the planet took to get into a particular temperature state. While the statement "the Earth was much warmer once than it is today" is demonstrably true (almost the whole planet was covered in rain forest at that point), it doesn't bear any relevance to modern climate change as that state was achieved over hundreds of thousands of years, giving the ecosystem a chance to adapt. The main concern is not so much the warming, but

        • by PPH ( 736903 )

          The last ice age lasted for 100,000 years. In total. The onset and ending of that ice age may have only taken a few hundred years. Perhaps as little as decades.

          The whole slow and steady geological change theory has been debunked. Geological features that people assumed took millions of years to occur turn out to have been created in a matter of a few days or even hours.

    • Re:0.55 C (Score:4, Insightful)

      by Ryzilynt ( 3492885 ) on Wednesday July 22, 2020 @11:17PM (#60321525)

      The climate alarmists believe the climate warms directly by 1.1 C per doubling of CO2 concentration and that an indirect feedback multiplier of 3x gets applied to this warming. The climate skeptics believe that the climate warms directly by 1.1 C per doubling of CO2 concentration and that an indirect feedback multiplier of 0.5x gets applied to this warming. Even intuitively, if the feedback multiplier were >= 1, the climate would have run away billions of years ago. The skeptic model matches observed reality and the alarmist model does not. So, the alarmists try to manipulate the data to create the missing warming.

      Yes if it weren't for 800,000 years of atmospheric co2 records in the ice cores your bullshit might have stood a chance. That and of course the fact that the industrial revolution only began 200 years ago.

      https://cdiac.ess-dive.lbl.gov... [lbl.gov].

      Yup , atmospheric co2 levels are more than DOUBLE any peak in the last 800,000 years, just in the last 200 years.

      Explain that shit away.

  • So opening new Artic Routes are a certainty. Along with explotation of resources there. So southern maritime routes, as they're hotly contended now are not that important as they are now as they will on the future. The next frontier is the north. Let's talk about that, and leave the fear of other things to professional alarmist activists.
    • Re:Artic Routes (Score:4, Insightful)

      by rtb61 ( 674572 ) on Wednesday July 22, 2020 @10:27PM (#60321423) Homepage

      Yeah, lets just ignore that flooding of coastal cities, with 3m of sea level rise. We are already going to get 1.5m but 3m is a whole new order of chaos.

      As you trap heat in, the temperature rise becomes more distributed and of course the greatest rise in temperature will be at the poles and the lowest rise of temperature will be at the equator.

      So the average is something like 3.0 degrees but at the equator it is more like 1.5 and the poles it is more like 4.5, the scope for rise at the poles is much higher because you distributing trapped heat, rather than adding new heat which would be more evenly distributed.

      Only psychopaths would ignore the destruction of global cities and pretend there is value in the artic that could ever replace it. The worst hit areas, the USA east coast, the entire east coast and sea level rise disaster. Japan, with all of it major coastal cities many on river delta flood planes. All those cities fronting the intermediate. All of South East Asia's coastal cities. Do you know who fares the best, Russian and China, they know it as well.

      Those who did it will hang for crimes against humanity and forget about delusions of getting past that, too many flooded underwater coast front mac mansions. Greedy fuckers will want to make those responsible pay, whilst they claim they were not, 'directly' responsible (they get to wipe out and take the stuff of those directly responsible, laws will change to make it possible and crimes against humanity will be deployed).

      • I don't know why you think China has less to lose than US in terms of coastal cities, especially if you count Hong Kong (which they get back soon) and Taiwan (which they will get back eventually). I agree about Russia though.
      • Yeah, it could cost a whole trillion dollars this century. At least according to the estimates of infrastructure damage floating around. And reduce GDP growth by about $1.5 trillion over the same period.

        $2.5 trillion over 80 years? Meh.

        The funny part is that those are the numbers being used to sell the Green New Deal, which will cost something like 30-40x more than it's supposed to save.

    • So opening new Artic Routes are a certainty. Along with explotation of resources there. So southern maritime routes, as they're hotly contended now are not that important as they are now as they will on the future. The next frontier is the north. Let's talk about that, and leave the fear of other things to professional alarmist activists.

      And yet in the last 200 years (since the industrial revolution) we have more than doubled the highest peak concentrations in more than 800,000 years.... there were many ice ages in the time..

      https://cdiac.ess-dive.lbl.gov... [lbl.gov].

  • by Mr. Dollar Ton ( 5495648 ) on Wednesday July 22, 2020 @09:36PM (#60321313)

    Why not post the "plain english summary" from the real effing article, submittard, instead of journo's ignorant interpretation thereof?

    Earth's global “climate sensitivity” is a fundamental quantitative measure of the susceptibility of Earth's climate to human influence. A landmark report in 1979 concluded that it probably lies between 1.54.5C per doubling of atmospheric carbon dioxide, assuming that other influences on climate remain unchanged. In the 40 years since, it has appeared difficult to reduce this uncertainty range. In this report we thoroughly assess all lines of evidence including some new developments. We find that a large volume of consistent evidence now points to a more confident view of a climate sensitivity near the middle or upper part of this range. In particular, it now appears extremely unlikely that the climate sensitivity could be low enough to avoid substantial climate change (well in excess of 2C warming) under a highemissions future scenario. We remain unable to rule out that the sensitivity could be above 4.5C per doubling of carbon dioxide levels, although this is not likely. Continued research is needed to further reduce the uncertainty and we identify some of the more promising possibilities in this regard.

    • Just FYI, the "journo" in question is not entirely ignorant:

      Scott has a master's in hydrogeology from the University of Wisconsin-Madison, and has worked as a hydrogeologist for the Wisconsin Department of Natural Resources and the Wisconsin Geological and Natural History Survey. In addition to teaching at Coconino County Community College and Northern Arizona University, he is Science Editor for Climate Feedback.

      That said, I agree that TFS misses the main point of the article, let alone the original paper.

      • by Livius ( 318358 )

        Perhaps the interpretation was wilfully ignorant. This is a "journalist" we're talking about.

  • Comment removed based on user account deletion
    • The question is how much the one billion population will grow in Africa with better health and wealth. It could quadruple or more by 2100.

      • It's been seen over n over that more educated, healthy, and wealthy populations have fewer children, usually to the point of not hitting replacement numbers.

        If you want to avoid more African famine and war then stop raping the continent for resources, build schools up to university level everywhere, stop shipping in weapons by the mega ton, and stop sending free shit so they can build a real economy.

        • Comment removed (Score:5, Insightful)

          by account_deleted ( 4530225 ) on Thursday July 23, 2020 @01:12AM (#60321683)
          Comment removed based on user account deletion
          • by Viol8 ( 599362 )

            The chinese are very busy at the moment helping those african dictators get ever wealthier and stay in power with the number of mining operations they've started in the continent. If the west had done it we'd have had the usual woke idiots complaining about imperialism but it seems ok for china to treat africans like virtual slaves paying them a pittance for their resources.

        • You're confused,the biggest enemies of Africa doing the mayem and murder and resource raping are other Africans. "Stop shipping in weapons by the megaton", that means there are people there buying weapons so they can kill each other. The problem with Africa is Africans.

          Population won't go down if there is religious mandate to subjugate women and breed. You missed the memo on flavor of religion growing there.

      • Comment removed based on user account deletion
  • by Pravetz-82 ( 1259458 ) on Thursday July 23, 2020 @01:57AM (#60321751)
    The effect of pure CO2 is one thing and definitely it is a good thing to understand how it works. CO2 however is not the only green house gas. At some point we might go over a threshold that causes massive release of methane, like thawing of the Siberia permafrost or warming oceans causing some methane hydrates to be freed up.
    If that happens, I fear, it might be a game over for us.
  • Studies have show that after the impact CO2 levels went up to somewhere over 1000ppm and this caused a 5C temperature rise which would be an absolute disaster for our current ecosystem and human civilisation:

    https://www.newscientist.com/a... [newscientist.com]

  • It doesn't matter if we have equilibrium at +12 degrees centigrade or not.
    We'd be screwed either way.

    These results may offer some insight into how global climate change in geological timespans balance out and may be helpful to understand some details, but it changes nothing for the problem at hand: Man made climate change is happening at an ever accelerating rate and we have to slam the brakes make a hard 180 turn if humanity and the current ecosphere are not to be royally screwed. That's a cold hard scient

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