Don't bother feeding the trolls who always bleat that climate models are wrong. Of course they're wrong. Everything is necessarily wrong at some level of detail. The demand for perfect climate models is every bit as much pseudo-science as Creationists going on about missing links. Every gap in the fossil record is a missing link. And if you find an intermediate fossil within such a gap, you now have two gaps, one on each side of it. Creationism is, in the memorable words of Wolfgang Pauli,
Not even wrong.
We have a new set of climate models coming out, and new techniques for validating and improving them, under the name Coupled Model Intercomparison Projects. Basically, that means that we are taking all of the best models, harmonizing their inputs, and doing massive computer runs to see which features of the models give us the most accuracy with the greatest efficiency. Then we can use those results to build and test improved models, and perhaps use them to guide policy.
That's where it has all fallen down in the past, of course.
The good news, however, is that every time we improve the models, we get better information on what path to take to deal with the problem, and the possible trends toward improvement. Models have told us how much we have to cut carbon emissions to stay within various temperature targets. When the US can put in a government that cares about such things, we will actually be able to discuss the urgency of the problem, and the level of investment needed.
What good are climate models that Denialist trolls always dismiss, along with every policy to do anything about the Climate Crisis? Well, what good are Denialist trolls? The answer to either question is more questions: Good for whom? For what purpose? What's it to me? I'm glad you asked. Good for you. 😄😄😄😄😄
What are we to believe? Denialist maunderings, climate models, or our lying eyes and instruments? Theoretical science, including building and testing models, is a necessary part of the scientific method, but its foundation is facts. And the foundation of solutions is also facts that we have.
Denialist trolls are supposed to be good for the owners of fossil fuel resources, to prevent those resources from becoming valueless. They have kept their profits up for half a century, but they are coming to the end of that road.
The models are good for scientists who want to know what's really going on in Nature. They can be useful to those who have to make decisions about Global Warming, including politicians who are supposed to set policy, those who carry out government policy, businesses doing the real heavy lifting on renewable energy and electric vehicles, and us.
The only practical use of climate models is to warn us of coming dangers. They are irrelevant for proving that global warming is happening. There you just point to the measurements. The land is warmer, the air is warmer, the oceans are warmer, the ice is melting from the equator to both poles, the oceans are increasingly acid. Storms and droughts and heat waves and fires are much worse, and there are more species going extinct.
But if you ignore the models and the evident dangers, as Denialists want us to do, you fail to address the problems.
In principle, models can guide us in selecting policy responses. But there we already know the answer: All of the above.
Carbon Brief:
CMIP6: the next generation of climate models explained
Climate models are one of the primary means for scientists to understand how the climate has changed in the past and may change in the future. These models simulate the physics, chemistry and biology of the atmosphere, land and oceans in great detail, and require some of the largest supercomputers in the world to generate their climate projections.
Climate models are constantly being updated, as different modelling groups around the world incorporate higher spatial resolution, new physical processes and biogeochemical cycles. These modelling groups coordinate their updates around the schedule of the Intergovernmental Panel on Climate Change (IPCC) assessment reports, releasing a set of model results – known as “runs” – in the lead-up to each one.
These coordinated efforts are part of the Coupled Model Intercomparison Projects (CMIP). The 2013 IPCC fifth assessment report (AR5) featured climate models from CMIP5, while the upcoming 2021 IPCC sixth assessment report (AR6) will feature new state-of-the-art CMIP6 models.
CMIP6 will consist of the “runs” from around 100 distinct climate models being produced across 49 different modelling groups. The effort is already a year behind schedule, and it appears increasingly unlikely that all the CMIP6 models will be available in time for inclusion in the AR6.
What is available is more informative each time, and the rest of the runs will get done as computing resources become available and code gets updated and improved.
The “coupled” in the name means that all the climate models in the project are coupled atmosphere-ocean GCMs. The Met Office’s Dr Chris Jones explains the significance of the “intercomparison” part of the name:
“The idea of an intercomparison came from the fact that many years ago different modelling groups would have different models, but they would also set them up slightly differently, and they would run different numerical experiments with them. When you come to compare the results you’re never quite sure if the differences are because the models are different or because they were set up in a different way.”
So, CMIP was designed to be a way to bring into line all the climate model experiments that different modelling centres were doing.
Pay no attention to the Denialist trolls who complain that the models aren't perfect, and want you to ignore your lying eyes. Neither are Quantum Mechanics or General Relativity or Euclidean geometry perfect models of reality. We have a good idea of where their limits are, and take care not to use them where they don't apply.
In the case of climate models, it is true that they are always wrong. Reality has been worse every time.
Q&A: How do climate models work?
COP25 Update
Not much happened in official channels over the weekend, when the conference was not in session. Activists, however, remain hard at it. The biggest target is getting China to abandon its perverse incentives in favor of coal. If we do that, there is every evidence that we can start cutting global coal consumption at the rate needed, something like 7% annually. We just had a record global decline of 3%, without a turnaround from China.
Second biggest is getting rid of carbon subsidies, and imposing carbon taxes.
The Guardian
The big ideas remain eliminating carbon subsidies and putting in carbon taxes, renewables, electric vehicles, storage, cement, steel, ammonia, hydrogen, and carbon sequestration, whether in trees, in soils, or in reactions with minerals to form stable carbonates.
The Guardian
Ten times more production capability for solar panels, wind turbines, and batteries would do a lot for the problem. Maybe a bit more. Enough to get current electricity production to 100% renewables in a decade, and keep on building as demand from not-so-poor-any-longer countries continues to grow. Finance for poor countries to ramp up lower-cost renewables, rather than Chinese financing for coal, would also do a lot.
Euronews