Once you understand that certain gases in the atmosphere act as a heat reservoir, then the obvious hypothesis is that trapped heat will increase if the amount of those gases increases. Since we know we're increasing some of those gases by burning fossil fuels, we expect warming.

There are only 2 ways to disprove this hypothesis. One would be to disprove the basic science of the greenhouse effect--not likely. The other would be to show that there is another climatic process that counteracts the expected warming. And to do that, you would need to create a more complicated model of the climate.

This is what scientists have done, and they haven't found any effect that fully counteracts the expected warming.

So just to be clear: computer models aren't important because they prove that global warming is happening. Warming is the base assumption. Computer models are important because they have failed to prove anything can stop it.

As for gravity, there is no analytical solution to the 3 body problem. NASA still uses numerical simulation to model the solar system--just like a climate model, but with many orders of magnitude fewer nodes and inputs. They can be so precise because their model is so simple, not because of a fundamental difference in scientific understanding.

Just like you don't need much of a model to predict that if a rogue planet passed through the solar system, existing orbits would be perturbed. Calculating the precise perturbations would be complex, but not predicting their existence.

Likewise, it's difficult to predict exactly how more heat in the atmosphere will change local weather. But it's not hard to predict that heat will build up if the gases build up.

Given that the earth has had temperature excursions of +4C and -4C in the past 100k years it seems that there are some kind of forces that keep the temperature within that range. What are they? Climatologists are saying "tipping points" and whatnot, but if you believe the very long climate history as measured by proxies you would have to admit that there certainly SEEMS to be something that stops the temperature from rising further, and something that stops it from falling further. What are those mechanisms?

The history of Earth's climate shows the limits of these changes, but that doesn't mean there are guard rails keeping us safe. It's just a reflection of the physical limits of the forcings and feedbacks. Our orbit only varies so much. Our axial tilt only wobbles so much. The sun's output only varies so much. The atmosphere can only hold so much water vapor at a given temperature. Etc.

If the sun suddenly doubled in brightness, I doubt you would expect the climate to still stay within that +/- 4C range, right? Well, atmospheric gases are also a forcing, one that we know we're changing. Granted--not at that level, but change is change. Models help us think about the sensitivity to that change, but the equilibrium must shift, somehow.

Anyway, the Earth's climate could stay well within that +/- 4C range, and the warming would still cause mankind a ton of trouble if it happens too fast. Remember that these are global average energy levels...it doesn't take much to raise sea level a troublesome amount, for example, especially since societies have built right at the water line all over the world.

Let's try it out: is human nutrition and metabolism settled? Nope. Do you want to feed your child a diet of 100% JIF peanut butter and candy corns until it is? I'm guessing not.

We don't need to get to settled. We just need to stop reasoning backward from the conclusion we want to be true. Especially when the consequences for things are as high as they are.

http://en.wikipedia.org/wiki/List_of_refrigerants

You'll notice on that list that there are numbers for the "Net 100 year GWP" which basically means how much more a particular substance could cause heating versus CO2, which has an index of 1.

You'll notice that there are a LOT of compounds on the list and numbers in excess of 100 are common, and in excess of 1000 are too. I've looked up a couple and a couple of them have non-trivial atmospheric concentrations. If something has 1/1000 the concentration of CO2 and a GWP number of 10x CO2 then it would contribute 1% as much. Over a list of about 1000 refrigerants if they all managed to be 1% (this is a stretch I know!) then you could get 10x the warming from refrigerants as from CO2.

I might argue that you've already reached the conclusion that you want to (we gotta do something), and are reasoning backwards from there (carbon emissions are the cause) yourself.

As another example, a lot of people think this project is funded by oil companies and employs professional climate deniers. http://www.surfacestations.org/ Why? Because they have the audacity to try and make sure that the temperatures gathered from weather stations aren't accidentally biased.

I personally think that's MORE important to the analysis than anything else you could do, because if the raw data's no good your conclusions are also no good. Put a bunch of crap detectors in the LHC and you can find whatever particle you want. But physicists don't do that do they?

I will only reiterate that if 1000 brain surgeons say X, you should probably believe X unless you have very particular reasons to believe you are way smarter than all of them and know things about brain surgery that they don't know.

And of course once in a great while that happens. There was a guy who first said that the earth was not flat, and all the other learned folks thought he was daft and then probably set him on fire or something. However, I have zero evidence to believe this accounts for any of the variance in the current moment in time, with climate, immunization, any of it. A far simpler explanation will do the trick, as mentioned in my original msg.

1. I'm trained as an engineer and a scientist. I've read a lot of papers and I've got a good grasp of significance.

2. I've seen experts be wrong before and I understand a lot of psychology to where I understand how they can be both wrong and fervently believe they're not. It took me two days to convince a biology professor (PhD) that he was performing a simple calculation incorrectly and that it was skewing all his results. He was doing log(A)/log(B) instead of log(A/B). It's the first rule: https://www.biogazelle.com/seven-tips-bio-statistical-analys...

3. Big models of big complex systems can have lots of interlinkages that aren't always apparent. If I let you analyze a Honda engine and come up with a model for it, if the engine never revved above I think 3000rpm you'd make a great model and have really high confidence that it was highly predictive. Then when revved to 6k and the engine diverged from the model you'd flip out and not understand what's going on until I told you that the engine has two different camshaft profiles and it can change between them. To you, who has only ever known that an engine has one camshaft profile and that it's fixed, this is madness!

I hope this analogy makes it clear that I don't think there's a big conspiracy but rather than a lot of people who are very earnest and very well meaning can get the wrong result through systematic problems that aren't immediately apparent.

I also think that some of those people might in their head say "look even if this isn't true, the risk that it COULD be true is so great -- I mean it's the whole planet! -- that we need to solve this problem anyhow" and then go ahead with that. And then they'll get extra impassioned because now they're on a mission to save the world! Can you imagine how motivating that would be?

The problem is that it seems like there's no downside: we fix CO2 and everything's great even if we didn't strictly speaking need to. The problem is that there is in fact a downside, a huge burden on everyone on the planet because we don't yet have cheap, reliable alternative energy sources. The first world only developed because of energy and it seems pretty shitty to deny the 3rd world the chance to develop because we don't want Venice to sink.

Personally I think that if you gave me the choice, to sink Venice and a few other cities and to bring the whole developing world up to developed world standards, that's a very tough choice. Is our art and investment in buildings more important than their lives?

Further the idea that tipping points exist which will catastrophically damage the climate is fair, but nobody's looking at it the other way either. Maybe there's some other linkage which will actually start to make the Earth shed heat faster once the temperature goes up three degrees.

http://en.wikipedia.org/wiki/Temperature_record#mediaviewer/...

http://en.wikipedia.org/wiki/Temperature_record#mediaviewer/...

If these are accurate, then the Earth's climate is actually VERY stable and there must be restraining forces as well as tipping points.

But I'm curious about something you said and would be interested in hearing you expand a bit on it if you're willing. You say (and I believe you) that you don't think there's a giant conspiracy; and you give an example of the Honda never revving past 3000, which, if one were to make the error you describe, is basically an illustration of a linear model with insufficient leverage to support the conclusions that are drawn from it. The Honda example is a good illustration of that problem, and I will steal it in the future.

For now, though, based on this example, and your point #2, I'm wondering how you think these kind of fundamental statistical and logical errors could be made on such a massive scale, by a huge group of scientists, distributed around the world?

The only way I can imagine such a thing being feasible is via some serious groupthink / path dependency; like if Einstein, Maxwell, and von Neumann were raised from the dead, transformed into climate scientists, and then, at the very start of the very first climate conference, one right after the other got up and loudly and confidently expressed certainty that climate change was caused by X. Such an event could theoretically lead subsequent scientists to parrot the new party line, and to have difficulty getting funded for research that diverted from these pre-conclusions about X.

That scenario obviously didn't happen. It seems exceedingly unlikely that anything comparable could happen on this scale. Of course, from time to time certain topics of inquiry go in or out of fashion, like the neural winter of the 90s and 2000s, which has ironically now reversed itself with the whole deep learning thing. But that happened because funding was coming principally from US funding agencies, the computational power and data was inadequate to demonstrate the value of the nascent techniques, and the body of research was overwhelmingly produced in US institutes, none of which apply here.

So I'm interested to know by what mechanism you think so many smart people who are also engineers and scientists, except also specialists in this very topic, are making fundamental logical and statistical errors?