• Redacted@lemmy.world
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    1 year ago

    And yet still the ice is melting faster than expected and faster than that model predicted, because, as you explain, the models are inaccurate (overly conservative in nature as all scientific studies on complex systems tend to be).

    • silence7@slrpnk.netOPM
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      1 year ago

      Ice sheet dynamics have been an area where scientists haven’t converged on agreed-upon models. So yes, not everything gets there, but an awful lot does. As I said above, enough to be useful.

      • Redacted@lemmy.world
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        1 year ago

        You seem to keep supporting my point.

        The models are conservative, the peer review process is long and we’re rapidly running out of time.

        • silence7@slrpnk.netOPM
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          1 year ago

          It’s more complicated than that. The temperature modeling is roughly right. Secondary effects aren’t as well modeled, and surprise is a lot more likely there.

          • Redacted@lemmy.world
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            1 year ago

            Yes it’s obviously way more complex than that. For instance, there are a lot of additional warming factors that haven’t been included in current studies or “suprises” to use your euphimism.

            • silence7@slrpnk.netOPM
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              1 year ago

              The big ones we expect to play a role in the next few decades are in there though. That’s enough to be pretty useful.

              • Redacted@lemmy.world
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                1 year ago

                Pretty useful, in that they predict warming but not necesarily accurate.

                I disagree, we do not know how well feedbacks are modelled or even if the models include all significant feedbacks. Correct me if you’ve found anything that contadicts these:

                • The albedo effect problem you mentioned is likely to happen faster than predicted as the latent heat of melting isn’t considered. The heat it requires to melt all that ice will instead heat the water around the remaining ice at a much higher rate.

                • IPCC doesn’t account for the aerosol cooling effect. If we cut our emissions there would likely be a rapid warming of 0.5-1.0°C within a couple of years as particulates in the air are blocking less sunlight.

                • The ice sheets don’t melt at a steady rate. Last time this much carbon dioxide was in the atmosphere they ended up retreating 600m per day which should affect predictions.

                • Not strictly a feedback loop but worth mentioning… The earth contains less than 20% of the copper needed to produce the renewables required to replace fossil fuels over the next 20 years, about 20% of the required nickel and less than 2.5% of the required lithium.

                • silence7@slrpnk.netOPM
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                  1 year ago

                  The albedo effect problem you mentioned is likely to happen faster than predicted as the latent heat of melting isn’t considered. The heat it requires to melt all that ice will instead heat the water around the remaining ice at a much higher rate.

                  Just no. Ice sheet response tends to be parameterized, where a computationally simple approximation is used, including this.

                  IPCC doesn’t account for the aerosol cooling effect. If we cut our emissions there would likely be a rapid warming of 0.5-1.0°C within a couple of years as particulates in the air are blocking less sunlight.

                  This is complete nonsense. They’ve been accounting for it for ages. That’s where figures like this come from.

                  The ice sheets don’t melt at a steady rate.

                  This is well known, and widely discussed.

                  Last time this much carbon dioxide was in the atmosphere they ended up retreating 600m per day which should affect predictions.

                  This appears to be from a single study of a particular set ice sheets off Norway which were grounded below sea level. Thwaites is like that, but much of the big ice sheets are not. Ice melt isn’t some simple thing which will happen at the same rate everywhere.

                  Not strictly a feedback loop but worth mentioning… The earth contains less than 20% of the copper needed to produce the renewables required to replace fossil fuels over the next 20 years, about 20% of the required nickel and less than 2.5% of the required lithium.

                  This is a serious misreading of what’s going on. There’s enough in the earth’s crust, but trying to depend only on existing mines would be a bottleneck. That’s why a ton of new mines are opening.