The linked PDF was not terribly detailed, but it more-or-less confirmed what I’ve long thought about climate change. Specifically: the mechanism by which atmospheric CO2 raises temperatures is well-understood and not really up for debate, as is the fact that human activity has contributed an enormous amount to atmospheric CO2. But the detailed climate models are all basically garbage and don’t add any good information beyond the naive model described above.
ETA: actually, I found that this is exactly what the Berkeley Earth study found:
The fifth concern related to the over-reliance on large and complex global climate models by the Intergovernmental Panel on Climate Change (IPCC) in the attribution of the recent temperature increase to anthropogenic forcings.
We obtained a long and accurate record, spanning 250 years, demonstrating that it could be well-fit with a simple model that included a volcanic term and, as an anthropogenic proxy, CO2 concentration. Through our rigorous analysis, we were able to conclude that the record could be reproduced by just these two contributions, and that inclusion of direct variations in solar intensity did not contribute to the fit.
I feel doubly vindicated, both in my belief that complex climate models don’t do much, but also that you don’t need them to accurately describe the data from the recent past and to make broad predictions.
I agree on not terribly detailed. It’s more of an “I checked, and Climate Change is correct” than a critical analysis. [I’ll reread it more carefully in a few weeks, but that was my impression on a first reading, admittedly while drugged up after surgery.]
Perhaps I’m looking for the impossible, but I’m not comfortable with the idea that climate is so esoteric that no one outside the field can understand anything between CO2 traps UV at one extreme … and the other extreme consisting of the entire model with conclusion that therefore the planet will warm by x degrees this century unless we eliminate fossil fuels. That alone has not satisfied many who ask—and it shouldn’t. I have more respect for my students (math-based but a different field) who search for more detail than for those who accept doctrine.
I can explain fusion on many levels: from hydrogen-becomes-helium to deuterium-and-tritium become helium to this is the reaction cross section for D-D or D-T or D-He3 and ____ MeV are released in the form of ____ …. Similarly for the spectrum from lift/drag to the Navier–Stokes equations …, and similarly for dynamic stability of structures. I am disappointed that climate scientists cannot communicate their conclusions at any intermediate level. Where is their Richard Feynman or (preferably) Carl Sagan?
But the detailed climate models are all basically garbage and don’t add any good information beyond the naive model described above.
That’s a strange conclusion to draw. The simple climate models basically has a “radiative forcing term”; that was well estimated even in the first IPCC reports in the late 80s. The problem is that “well-estimated” means to ~50%, if I remember correctly. More complex models are primarily concerned with the problem of figuring out the second decimal place of the radiative forcing and whether it has any temperature dependence or tipping points. These are important questions! In simple terms, the question is just whether the simple model shown breaks down at some point.
I don’t think actually reading the literature should convince anyone otherwise, the worst charge you could levy is one regarding science communication. I mean, I don’t think anyone from the climate community would dispute the fact that the early IPCC reports, which were made before we had access to fancy computers, did actually predict the climate of the 21st century so far remarkably well: https://www.science.org/cms/asset/a4c343d8-e46a-4699-9afc-983fea62c745/pap.pdf
The other aspect is that the ~50% (ballpark) uncertainty in the forcing, back then, allows for good near-term projections but the projections diverge after more than a couple decades, and we really want to have a better handle on things with a longer time horizon.
Finally, you can see that sea-level projections weren’t quite as good. Detailed modelling is a bit more important there.
The linked PDF was not terribly detailed, but it more-or-less confirmed what I’ve long thought about climate change. Specifically: the mechanism by which atmospheric CO2 raises temperatures is well-understood and not really up for debate, as is the fact that human activity has contributed an enormous amount to atmospheric CO2. But the detailed climate models are all basically garbage and don’t add any good information beyond the naive model described above.
ETA: actually, I found that this is exactly what the Berkeley Earth study found:
I feel doubly vindicated, both in my belief that complex climate models don’t do much, but also that you don’t need them to accurately describe the data from the recent past and to make broad predictions.
I agree on not terribly detailed. It’s more of an “I checked, and Climate Change is correct” than a critical analysis. [I’ll reread it more carefully in a few weeks, but that was my impression on a first reading, admittedly while drugged up after surgery.]
Perhaps I’m looking for the impossible, but I’m not comfortable with the idea that climate is so esoteric that no one outside the field can understand anything between CO2 traps UV at one extreme … and the other extreme consisting of the entire model with conclusion that therefore the planet will warm by x degrees this century unless we eliminate fossil fuels. That alone has not satisfied many who ask—and it shouldn’t. I have more respect for my students (math-based but a different field) who search for more detail than for those who accept doctrine.
I can explain fusion on many levels: from hydrogen-becomes-helium to deuterium-and-tritium become helium to this is the reaction cross section for D-D or D-T or D-He3 and ____ MeV are released in the form of ____ …. Similarly for the spectrum from lift/drag to the Navier–Stokes equations …, and similarly for dynamic stability of structures. I am disappointed that climate scientists cannot communicate their conclusions at any intermediate level. Where is their Richard Feynman or (preferably) Carl Sagan?
That’s a strange conclusion to draw. The simple climate models basically has a “radiative forcing term”; that was well estimated even in the first IPCC reports in the late 80s. The problem is that “well-estimated” means to ~50%, if I remember correctly. More complex models are primarily concerned with the problem of figuring out the second decimal place of the radiative forcing and whether it has any temperature dependence or tipping points. These are important questions! In simple terms, the question is just whether the simple model shown breaks down at some point.
I don’t think actually reading the literature should convince anyone otherwise, the worst charge you could levy is one regarding science communication. I mean, I don’t think anyone from the climate community would dispute the fact that the early IPCC reports, which were made before we had access to fancy computers, did actually predict the climate of the 21st century so far remarkably well: https://www.science.org/cms/asset/a4c343d8-e46a-4699-9afc-983fea62c745/pap.pdf
The other aspect is that the ~50% (ballpark) uncertainty in the forcing, back then, allows for good near-term projections but the projections diverge after more than a couple decades, and we really want to have a better handle on things with a longer time horizon.
Finally, you can see that sea-level projections weren’t quite as good. Detailed modelling is a bit more important there.