A new analysis by Hansen and colleagues concludes that both the impact of recent cuts in sun-blocking shipping pollution, which has raised temperatures, and the sensitivity of the climate to increasing fossil fuels emissions are greater than thought.

The group’s results are at the high end of estimates from mainstream climate science but cannot be ruled out, independent experts said. If correct, they mean even worse extreme weather will come sooner and there is a greater risk of passing global tipping points,

Evwrtyhings on course for the collpaee if civilisation under the weight of human stupidity :)

  • sp3ctr4l@lemmy.zip
    link
    fedilink
    English
    arrow-up
    7
    ·
    edit-2
    19 hours ago

    Disclaimer: I am not a climate scientist, there appears to be one in this thread, maybe he could comment, that being said:

    Yep.

    You are correct, that was the consensus a few years back.

    Then, things kept getting worse than what that consensus would suggest.

    In 2020, +2 to +4.5 C by 2100 was generally the consensus.

    Heres an article in Nature from 2022.

    https://www.nature.com/articles/s41598-022-16264-6

    For each CMIP, two climate scenarios were considered: a middle-of-the-road scenario with effective GHG emission reductions, and a business-as-usual scenario with virtually no GHG emissions reductions. These scenarios correspond to SRES B1 and SRES A2 for CMIP334, RCP4.5 and RCP8.5 for CMIP517, and SSP2-4.5 and SSP5-8.5 for CMIP618, respectively.

    Figure 1 shows that, for all CMIPs and scenarios, the observed warming generally fits well within the projected warming range, and closely follows the CMIPs median warming lines. The observed warming is usually closer to the upper level of the projected warming ranges. Considering the average warming for the whole future period, CMIP3 SRES B1 (SRES A2) average warming is 0.20 °C (0.17 °C) lower than the observed one, while for CMIP5 RCP4.5 and RCP8.5 the average warming is 0.07 °C and 0.06 °C lower than the observed one, respectively. CMIP6 SSP2-4.5 and SSP5-8.5 average warming is 0.17 °C (0.14 °C) lower than the observed one.

    Thus, all CMIPs temperature projections up to 2020 are slightly conservative, particularly CMIP3. However, it should be noted that CMIP6 future period comprises only 6 years, which is relatively short to draw solid conclusions.

    Emphasis mine.

    Here’s the older RCPs from the IPCC in 2013

    Unfortunately I am on a shit tier phone and cannot pull data and compose/plot my own graphs comparing actual data with model projections… but uh yeah, its looking to me that actual real world temperatures are at best following basically the worst case model scenarios in the last few years… and might even be breaking out, upwardly, of the 95% confidence channels for even those, if something like +1.75C this January is not just some weird fluke, and is indicative of the trend of all of 2025.

    That would mean we’d hit +2.0C by or before 2030, the graph goes exponential, hockeysticks, much, much more soon than the current consenus projection models.

    Again to repeat that disclaimer: I am not an expert, but I am extremely concerned. The way I see it, following climate science related news for about 2 decades now, it seems to me there is a fairly well established tendency for the consensus to actually be too optimistic. Almost everyone keeps being surprised, almost year after year, by actual data, actual events being worse than consensus projections.

    I almost died in the heat dome in the PNW a few years back. Am poor. Do not have AC. Have health conditions.

    Spent 3 straight days, inside, with blackout curtains and reflective solar blankets up on the windows… it was over 90F-95F at night, up to 105-110F during the day.

    I lost 10 pounds from sweating in 3 days.

    Nothing like that had ever happenes before in recorded PNW history, and the knee jerk response at the time from almost every climate scientist that commented on it was ‘well actually thats just a weird freak one time thing and we can’t actually attribute it to global warming’ … and since then just all over the US, insane climate events keep happening regularly that 20 years ago would have been ‘once in a life time.’

    My strong, unprofessional suspicion is that we are literally cooked.

      • sp3ctr4l@lemmy.zip
        link
        fedilink
        English
        arrow-up
        4
        ·
        edit-2
        18 hours ago

        Didn’t even register your username.

        Go look up how the arctic permafrost is rapidly melting, releasing ungodly amounts of methane, which is roughly 70x more potent a greenhouse gas than co2.

        A couple years ago now I first saw that rivers in Alaska were being reported as running a kind of bronze/orange color… go look up ghost/zombie forest fires, where forests in siberia, alaska and canada are burning down from the inside out, from underground methane that catches on fire.

        • HasturInYellow@lemmy.world
          link
          fedilink
          English
          arrow-up
          4
          ·
          14 hours ago

          I love all the stuff you have posted, I just have one small correction, methane has about a 30x stronger GHG effect than CO2. I also believe we are fully cooked for all the reasons you laid out. It’s honestly keeping me quiet a bit more calm during the current shit show in the USA.

          Even in the worst possible case scenario with that, they will get 10-20 years of ruling at best before they are undone by their own hubris. I really think that in the next decades hurricanes are going to go ape shit and one will actually LEVEL Miami. I mean shit, with sea water rising and flooding skyscraper basements, eating away at concrete and steel, a strong enough hurricane could topple one right over.

          • sp3ctr4l@lemmy.zip
            link
            fedilink
            English
            arrow-up
            3
            ·
            edit-2
            14 hours ago

            I saw 72x in the last article I read mentioning it, can’t find it, MIT says 84x CO2 for the first 20 years.

            In the first 20 years after it enters our atmosphere, methane will trap around 84 times more heat, pound for pound, than carbon dioxide (CO2), the best-known greenhouse gas.

            https://climate.mit.edu/ask-mit/how-much-methane-do-human-activities-put-atmosphere

            The point is that its kind of like a bullet:

            CO2 heats up the atmosphere up to a point, thats like a hammer being cocked back slowly while your finger is on the trigger.

            Atmosphere hits a certain tipping point, apparently it was about +1.5C, at that point the hammer swings and hits the primer, primer then ignites the much, much more powerful gunpowder.

            Gunpowder going off is what actually fires the bullet, sends temps and other feedback loops into overdrive very fast.

            Gun is pointed at our head.

            But anyway, damn the details, we do appear to be well and truly fucked.

            I keep laughing any time any news commentator says ‘history will look back at X and think…’

            There’s not gonna fucking be any history, any historians, 100 years from now, at the rate we are going.

            • HasturInYellow@lemmy.world
              link
              fedilink
              English
              arrow-up
              2
              ·
              edit-2
              6 hours ago

              I literally looked it up before I corrected you but who fucking knows honestly. Maybe I did a piss poor job. Bottom line is, we fucked, bigly.

              I think the exact thing with all the news. In some morbid sense, those being killed now and in the near future are just skipping the line and avoiding the rush. They don’t have to see how truly UGLY it will get towards the end.