Earth is Warming. I guaranty we don't know Earth's current temperature, not on the surface, not in the atmosphere generally, not from the surface to the edge of space, and certainly not in the entire volume thereof. What I can't know is how accurate our estimates are and what the real margin of error is (the calculated margin is nonsense).
I guaranty we don't know what Earth's temperature was in any of the those volumes as a historical matter (and some are completely impossible to have measured given the way we indirectly measure historical temperatures). What I can't know is the margin of error on the estimates, or whether the indirect measurements we do are less accurate than the direct ones we are attempting now, or even if they are more accurate. It's literally possible that the indirect historical measures actually encode more relevant data than the real time measures, of course it's literally possible they're completely noise.
I guaranty, the way we have built the models using micro data research is heavily biased towards that which we easily understand, can get too or have researched, which is a heavy bias. What I can't know is what else is out there, or if we by random chance have pieces of it correct.
Putting that aside, let's assume that we are in fact warming (and there are plenty of people that make reasonable cases this is not the case, and others who make nutty cases), then that leads to the question of what's causing it.
These are very erudite criticisms of our state of knowledge, but I believe they exaggerate the uncertainty, for two reasons.
First, what do you mean by "know?"
When you say, "we don't know Earth's current temperature, not on the surface, not in the atmosphere generally, not from the surface to the edge of space, and certainly not in the entire volume thereof," exactly
how much don't we know? For instance, let's say we measure the temperatures in Detroit and Chicago to a tenth of a degree, and they are both at 98 degrees F. Does that mean we have no idea of the temperatures between those cities? Could there be a field in between that is at -40 degrees, for instance? Of course not. We know enough about thermal dynamics and weather to know that such an anomaly would be readily detectable through winds and such. Not to mention satellite measurements. And not to mention the thousands of people who pass through the areas every day, none of which have ever frozen to death between those cities on a hot summer's day.
So while you object that "I can't know is the margin of error on the estimate," you can know that there are outer bounds on those estimates. So you can't completely discount all measurements and extrapolations from them.
Second is that models are a legitimate way to conduct science. Or do you believe the entire field of astrophysics is not "science?"
I mean, exactly which of your objections do not apply to our knowledge that the sun is primarily run by fusion of hydrogen atoms? We don't "know" its temperature. We don't "know" the actual margins of error. We don't "know" if the models we created using micro data isn't heavily biased. And we certainly don't know if there are unknown unknowns that could be the
real reason the sun shines. But does anyone question the consensus that we do know how the sun shines? Even you?
And what about black holes, background radiation, supernovas, etc. Don't we "know" anything about them? Or is all we know is that there are shiny things in the sky?
I also noticed something you didn't guarantee above.
You didn't guarantee that AGW
isn't happening.
This is important, because there are a few things I can guarantee, too.
I can guarantee that CO2 levels in the atmosphere are increasing. We have the measurements.
I can guarantee that CO2 is a greenhouse gas. We have over a century of research about that.
So I can guarantee that CO2 is trapping more heat in our atmosphere than it did in centuries past.
No matter what the other data says, it doesn't change these facts.
Caused by People. That's our second "consensus" item. It's caused by people. This by the way is almost completely reliant on a single correlation. As the human population's technology and pollution have increased the "measurements" we are able to do appear to have increased. That's it. There's no experiment that confirms it. So how do we get from correlation to causation? Well honestly we can't.
However, we can approach the limit by eliminating other potential causes (again assuming we are even correct about the temperature). As with any purely observational Science, we become more certain of a theory by eliminating other potential causes as a source. And that's the whole lot of what is going on. If the correlation breaks the theory falls apart (which is why things like a "pause," a medieval warm period, and historically far higher carbon concentrations at lower temperatures are so damaging that they have to explained away).
Modelling though? Total red herring, and literally not a science experiment. It generates zero data. It runs zero experiments. It settles zero factual questions. What it may be good for is generating hypothesis, and if we get tuned enough correctly making predictions. I personally don't believe it's close to there yet, but reasonable people can disagree.
Why is it dangerous to treat this "consensus" as meaningful? Well mostly because we only know of a correlation and have not shown a causative effect. That means that contrary evidence will either "break" the model completely, or lead to "narrative explanations" of things that altered the course (whether these are actual refinements, or literally just covering for a broken hypothesis is in the eye of the beholder). If it's just a false correlation, and we implement ridiculous and damaging policies, they will (a) do no good, and (b) be credited with any correlative change.
So if we do nothing, and nothing happens. Proof it was a mere correlation. If on the other hand we completely rearrange the world, destroy all economies and kill have the population, and nothing happens. Proof we "saved" the world.
On the flip, if there is a causation and we do nothing it gets worse. But if we "do something" and it's the wrong thing it will also get worse and maybe much worse (which is why I'm so opposed to international treaties that punish the most efficient producers).
But let's not kid ourselves. Consensus on AGW is literally consensus on a hypothesis, and literally one that's incapable of being tested.
Except that it is far, far more than simple correlation. We
know that CO2 traps heat. So we expect that increased levels of CO2 will trap more heat. That is not just correlation.
Here's a thing that we don't emphasize enough. The computer models of our climate are not intended to "prove" that global warming is occurring. What I stated previously "proves" that. What the computer models can do is help us better understand exactly how it is affecting our climate, in greater detail. They might even show that there are other factors that mitigate our emissions of billions of tons of CO2 and it is not warming our planet. Dig it:
the computer models are our best chance of showing that AGW is not occurring. Otherwise, we are left with those basic facts above. And they all point to AGW being true.
And while there are other sources of CO2 than our emissions, nevertheless
we are still emitting billions of tons of CO2 each year. Any natural source
increase the global warming effects. And other source of heat
increases the temperature increases we are creating.
We
know we are trapping more heat in our atmosphere. The only question is how much and how quickly. A good model of our climate system will help us get a more accurate answers to those questions, and maybe even show that we actually aren't affecting the overall system. But so far, the models haven't. And until they do, we have to assume that the basic physics is correct, that the models are reasonably accurate, and that we are the main cause of rising temperatures on Earth. To do otherwise is to kid ourselves.
