Posted on 09/13/2025 8:09:56 AM PDT by Oldeconomybuyer
Global climate models are software behemoths, often containing more than a million lines of code.
Inevitably, such complex models will contain mistakes, or "bugs." But because model outputs are widely used to inform climate policy, it's important that they generate trustworthy results.
Ulrike Proske and Lieke Melsen set out to understand how climate modelers think about, identify, and address bugs. They interviewed 11 scientists and scientific programmers from the Max-Planck-Institut für Meteorologie who work on the ICON climate model for their study published in Earth's Future.
When new code is developed for ICON, it's screened and tested to catch bugs before being integrated into the model itself, the interviewees said. After code is integrated, however, such testing usually stops.
The code is assumed to be bug free until the model behaves weirdly or a programmer serendipitously discovers a bug while examining the code for other reasons. Even when the model crashes, it's not necessarily a sign that a bug needs to be fixed, because researchers are always making trade-offs between the speed and the stability of the model, and sometimes they simply push the model outside the bounds of what it can handle given those constraints.
Tracking down bugs and fixing them can be time-consuming, so even if the team suspects the presence of a bug, they sometimes estimate its impact to be minor enough that it doesn't warrant correction. When the researchers do decide to fix a bug, many view the process as an extension of climate science: They generate hypotheses about how the bug might cause the model to behave, then test those hypotheses to discern the exact nature of the bug and how to address it.
The best way to avoid bugs is to test code thoroughly before it's integrated into the full model, many interviewees said. Tools exist to facilitate testing, such as Buildbot and the GitLab development platform, and the scientists said such tools could be leveraged more fully in ICON's development process. However, they also said there are inherent limits to how thoroughly researchers can test climate models because researchers don't always know what a 100% accurate model output would look like. Thus, they do not have that basis to which they can compare actual model output.
Though the interviewees acknowledged that ICON is imperfect, they also considered it to be "good enough" to forecast weather or to answer research questions such as how increased atmospheric carbon will affect global temperatures. The authors write that although "the principle of 'good enoughness'" is pragmatic and understandable, it could also lead to misunderstandings if users don't appreciate a model's limits.
Out of all climate models, the one which is in the most in agreement with reality is some Russian one.
All the others are not really testing against reality, but against each other. So they all agree!
They are programmed to agree!
That’s why they are black boxes. The peasants just wouldn’t understand.
“Predictions are very hard, especially about the future.”
Niels Bohr.
They are “good enough” when they can be used to expand government control, raise taxes, and produce trillions of dollars for “green” companies and their crooked political insider traders.
When past climate data follows the model. Todays models do not. The climate models are politically biased by design and not honest science.
When it predicts ANYTHING without jiggering the results after or the input before.
All depends on the organization.
When it can predict past weather. None of the climate prediction models used today or in the past can do that.
The climate has been warming relentlessly, since the end of the last glacial period. It will continue to warm until the Earth enters the next, inevitable glaciation. There is no action humanity can take to abate this certainty.
“good enough for government work”
Simple answer... Never!
Conjecture is not acceptable.
You can tell me what the weather is today... And you can tell me what the weather was yesterday in particular part of this world... But you can not tell me what the weather will be like tomorrow in any location anywhere on this planet with any certainty.
Concur.
Article: “climate policy”...
“Climate policy” always ends up with us eating bugs and the elites flying private jets to climate conferences and owning multiple mansions.
I have had quite enough of their “climate policy”.
When is it good enough?
Well, from the ‘scientists’ point of view, it is good enough when it gets you a government grant, or a payment from the enemedia for publishing rights.
Precisely correct. When a NOAA satellite gave billions of data points that did not support the global warming mantra, they declared it was a satellite error and adjusted the data to reflect their truth. How in the hell do they know it was an error without examining the satellite? The real truth could easily found by launching another satellite with identical instrumentation and get new readings. They did not!
They do lie, not in error but in malice.
The normal climate of the earth for many glacial epochs is glacial with brief interludes of warming we have today. If geologic history is a valid predictor (it is) we are on the cusp of a new glacial epoch. It will be long and cold as the warming periods are brief.
Pray for global warming as glacial periods are very hard on life.
ps
Per Al Gore the Arctic should be ice free by now in the summer. Why do Russia, Canada, and the USA deploy icebreakers in the arctic as I type? Are great ships crossing the arctic today? No!
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.