This is my crude attempt at the Big Big Picture (thanks to Larry Marder for the name) of our actual circumstances, focusing on climate. (There are other slices through it that are equally daunting, and they have similar shapes.)
The point is to think of the world as a feedback control system, with nature as the plant, humans as the feedback loop, and economic behavior as the actuator. Once you think of it this way (as Norbert Wiener himself would attest were he still with us) that vision never quite goes away. Of course, the rigorous mathematics of feedback systems for which Wiener was renowned is very hard to apply at the level of complexity we have here. Nonlinearity is the least of our problems!
Focusing on the carbon dioxide slice of our problem, only one part of the diagram becomes simple. That is CO2 concentration in the atmosphere, which reduces to a single number. All the other pieces of the system are immensely complicated.
Now IPCC working group I deals with the climatology and geochemistry parts of the system. These parts are relatively mature science. I would maintain that at the level of the Big Big Picture these are the best understood components of the system by far. Yet these are the parts that are the target of most of the controversy. Why is this?
It cannot be because the feedback system is working well. If it were, we’d be much more concerned about the great uncertainties in the realm of consequences (WG II) policies (WG III) and journalism and politics (not IPCC’s business at all). No, the focus on the physical science, the effort to paint it as a conspiracy, comes from the failure of not-IPCC parts of the system: journalism and politics.
The attention goes to the wrong place because all the impacts flow through the climatology block. If the climatology block is replaced by an open loop, people convince themselves there will be nothing to worry about. Here is where the delusion really strikes. The problem is not the block of climatology as a culture or a profession. The problem is the climate system, which will continue to react whether we continue to study it or not!
Of course, climate change is slow and continuous, and is swamped by the normal variation of seasons and by the ringing of the system as we keep hitting it harder. Perception of climate change is notoriously unreliable. The fact that the change is accelerating doesn’t make us, as individuals, better observers of it.
So if the information flow from climate as a discipline is stanched, the effort to come up with a realistic evaluation of our risks at the political level is effectively stymied. This is, in practice, not done at the obvious spot where climatology informs its client disciplines. It’s done by journalistic malpractice, disrupting the political process.
There’s the inconvenient problem that CO2 chemically disrupts the ocean as well. This opens up a second front of obfuscation, which is now being handled nicely by making a great deal of noise about climate science.
A good understanding of feedback control and a good understanding of the time constants of the components leads to the conclusion that we are entering very dangerous territory, and are now incurring consequences that will not be realized for decades to come. This sort of thing is quite unfamiliar to the political system under the best of circumstances.
Against this model we have a peculiar set of suggestions 1) that climate science has been corrupted in such a way as to grossly misrepresent the scope of likely consequences 2) that a similar corruption applies in marine geochemistry 3) that in the presence of this corruption the appropriate strategy is to treat the sensitivity of the systems to CO2 as near zero and 4) that the best thing to do under such circumstances is to muck around in people’s emails and nitpick a few marginal conclusions in reports of the other working groups.
The amazing thing is that great swaths of the press treat this position as something other than what it obviously is, a plague of red herrings from desperate people. I’ve always thought journalism was important. What we are seeing is not primarily a failure of science. We are seeing a failure of science communication and a victory of malice and slander. We are seeing a situation in which there is a desperate need for journalism to rise to the occasion, and in which there has been, so far, a desperate failure to do so.