I once read a story about Mick Jagger noting that he always and only slept with models. Asked why he replied "because he can". It may be that this has something to do with the state of climate science.

There was an outfit called the Institute for Energy Analysis at Oak Ridge. I visited Oak Ridge many times, and worked with those people, and I thought they were excellent. And the beauty of it was that it was multi-disciplinary. There were experts not just on hydrodynamics of the atmosphere, which of course is important, but also experts on vegetation, on soil, on trees, and so it was sort of half biological and half physics. And I felt that was a very good balance.

And there you got a very strong feeling for how uncertain the whole business is, that the five reservoirs of carbon all are in close contact — the atmosphere, the upper level of the ocean, the land vegetation, the topsoil, and the fossil fuels. They are all about equal in size. They all interact with each other strongly. So you can’t understand any of them unless you understand all of them. Essentially that was the conclusion. It’s a problem of very complicated ecology, and to isolate the atmosphere and the ocean just as a hydrodynamics problem makes no sense.

Thirty years ago, there was a sort of a political split between the Oak Ridge community, which included biology, and people who were doing these fluid dynamics models, which don’t include biology. They got the lion’s share of money and attention. And since then, this group of pure modeling experts has become dominant.

I got out of the field then. I didn’t like the way it was going. It left me with a bad taste.

Syukuro Manabe, right here in Princeton, was the first person who did climate models with enhanced carbon dioxide and they were excellent models. And he used to say very firmly that these models are very good tools for understanding climate, but they are not good tools for predicting climate. I think that’s absolutely right. They are models, but they don’t pretend to be the real world. They are purely fluid dynamics. You can learn a lot from them, but you cannot learn what’s going to happen 10 years from now.

Emphasis added. This is a useful summation of much of my understanding and concern about climate issues, and I too think that climate science is in bad odor as well as bad taste. The practitioners don't seem at all like scientists to me, they seem more like politicians or TV pitch men selling gadgets. Grifters like Al Gore are not an aberration, they are suitable representatives of the field, though Billy Mays might be more effective.

We know that plants do react very strongly to enhanced carbon dioxide. At Oak Ridge, they did lots of experiments with enhanced carbon dioxide and it has a drastic effect on plants because it is the main food source for the plants... So if you change the carbon dioxide drastically by a factor of two, the whole behavior of the plant is different. Anyway, that’s so typical of the things they ignore. They are totally missing the biological side, which is probably more than half of the real system.

Indeed. And it is complicated. Consider: CO2 concentrations don't have to fall very far below current levels before plants simply stop photosynthesizing. It costs more than it's worth when carbon, their primary food, is too scarce. It's always scarce - measured in parts per million while other gases such as oxygen, their main waste gas, is measured in parts per hundred - but a drop in concentration from current levels increasingly retards growth until it stops at about 200 ppm. Conversely, as concentrations rise photosynthesis and growth increases up to about 1,000 ppm. Greenhouse operators intentionally enrich the CO2 in the air for this reason.

Still, everything affects everything, and the effects are difficult to predict not only because availability of water and other nutrients can limit them, but also because all of the life forms above and below the soil surface adapt, adjust and evolve. Worse, it's not evenly distributed. There can be a local CO2 famine due to rapid uptake by life in a system in which CO2 is generally plentiful. The same is true for all other nutrients as well. Even light availability is locally variable, an obvious fact since everyone understands shade, but the systemic affects of variable light when trying to understand and predict the functioning of a large system is daunting. It is only recently that the effects of diffuse light due to aerosols have been grasped in any useful way and it is counterintuitive - diffuse light increases total growth.

Climate "scientists" either ignore all of this or crudely account for it with various fudge factors that are less educated guesses than SWAGs, or worse. If their predictions turn out to be anywhere near correct it will be a coincidence with little or no causal connection.

Things are changing, there have been effects from the various anthropogenic drivers and there will be more. Atmospheric concentrations of gases, land use effects, albedo alterations etc. etc. change the environment in non-obvious and often unimagined ways. We ought to be thinking about and studying these subjects. Sadly, we do not seem to be doing so in any credible way.

it’s a fact that they don’t know how to model it. And the question is, how does it happen that they end up believing their models? But I have seen that happen in many fields. You sit in front of a computer screen for 10 years and you start to think of your model as being real. It is also true that the whole livelihood of all these people depends on people being scared. Really, just psychologically, it would be very difficult for them to come out and say, “Don’t worry, there isn’t a problem.” It’s sort of natural, since their whole life depends on it being a problem. I don’t say that they’re dishonest. But I think it’s just a normal human reaction. It’s true of the military also. They always magnify the threat. Not because they are dishonest; they really believe that there is a threat and it is their job to take care of it. I think it’s the same as the climate community, that they do in a way have a tremendous vested interest in the problem being taken more seriously than it is.

I call it "function lust", and it does happen in every field. People want to do what they do, want to exercise their competencies and will invent reasons to do so if need be. Politicians and entrepreneurs see opportunities to exploit that function lust in the time honored way using hobgoblins to frighten the public in order to sell them snake oil charms and cures. In one sense it's just a normal senseless mania with which humanity is periodically and predictably afflicted - the herd stampedes for no good reason but once it starts it can't easily be stopped so it will run its course before the herd gets tired of it and settles down sheepishly to munch the grass again.

It may be that things aren't as grim and hopeless as they seem. Humanity will not change - function lust will not abate, opportunists will not stop exploiting fear, and manias will sweep through the herd as always - but the cycles may be quicker due to improved communication. Fads come and go more quickly, doing less harm than when longer lasting. It may be that careful thinkers would do well to pay more attention to these longer and larger cycles of change than to passing fashions. Advances in other sciences - materials science, biotech, nanotech and computing - as well as the information and communication advances may have far larger impacts. Even if the climate alarmists have accidentally hit upon a real issue it may not be much of a problem in the end due to other scientific advances. All speculative, but sufficient reason not to simply lose hope and despair that humanity is doomed by its own foolishness.