Prof. Stefan Rahmstorf
How the climate models of 20 years ago performed for global temperature.
Black line is the model average; as it is an average it is smoother than the actual data, which include more of the random variability which is superimposed on the warming forced by greenhouse gas emissions.
Feb 5, 2023 at 9:55amWeb
Show threadProf. Stefan RahmstorfFeb 5, 2023
The article describing this by NASA's @ClimateOfGavin is here: https://www.realclimate.org/index.php/archives/2023/02/2022-updates-to-model-observation-comparisons/?unapproved=809269&moderation-hash=cd7526a3229b2daa589bf0361336fbb6#comment-809269
RealClimate: 2022 updates to model-observation comparisons

RealClimate: Our annual post related to the comparisons between long standing records and climate models.

RealClimate | Climate science from climate scientists...
Show threadArneBabFeb 5, 2023

@rahmstorf This is awesome performance — much better than expected from the uncertainties.

Which actually gives me hope that the projections could stay being that good so we don’t get the 5% worst possibilities in the uncertainty enfolding …

Show threadmsjaewaFeb 5, 2023
@rahmstorf one question is the average of all data in the greyish-blue background?
Show threadSteven MolnarFeb 5, 2023
@msjaewa @rahmstorf It's explained in the linked article.
Show threadSir Snackosaurus of EatalotFeb 5, 2023
@rahmstorf and the horrifying thing is: Even if you turn it upside down the scale will go up and up and up.
Show threadStarry Starry KnightFeb 5, 2023
@rahmstorf Impressive fit overall but especially at the 1989ish downward trend❗
Show threadAriaflameFeb 5, 2023
@Space6host @rahmstorf You did see when it was run, right?
Show threadanlomedadFeb 5, 2023
@Space6host @rahmstorf
Ah, but it's from a model from "20 years ago", as Rahmstorf wrote. So the model was fed the actual data up to 1999, (including the 1989 drop,) and from then on, it calculated its future.
Show threadkampfschwaetzerFeb 5, 2023
@rahmstorf
And when we think back: In the 80's and 90's, so many of the konservative politicians said: This are horror scenarios. So the climate will never change. And now, when they are proven wrong: Did any of them apologize? Did #CDU, #CSU oder #FDP change their position? No. They just ignore the facts and spread lies. How incredibly irresponsible.
Show threadSergio VallespinFeb 5, 2023
@ralph @rahmstorf We are doomed.
Show threadkampfschwaetzerFeb 5, 2023
@svallespin @rahmstorf
When we are dead, we are doomed. Until then: We have to work on fixing the problems. anything else is not acceptable from an ethical point of view.
Show threadMatt WillemsenFeb 5, 2023
@rahmstorf Where does Exxon's model fit on this?
Show threadCarlos JiménezFeb 5, 2023
@rahmstorf impressive! So which of the models performed best in hindsight? Or were they all significantly off and only the average ended up being close to what really happened?
Show threadDevFeb 5, 2023
@rahmstorf they're proving the last of us very true about cordycep mushroom 👴
Show threadDr. MichelFeb 6, 2023
@rahmstorf very good match. It is a pity that we as a society didn’t work against climate change. We are really lost.
Show threadStarry Starry KnightFeb 7, 2023
@rahmstorf The time span of the model is retrospective to 1970. It was not fed real data else the red line and black line would match perfectly. The professor's point is the demonstration of the efficacy of the model both prospectively and retrospectively from a point in time 20 years ago.