One of humanity’s favorite illusions is that of knowledge. Humans think they know more than they actually do. Chabris and Simons (2009, Ch. 4) describe an experiment in which people were asked to rate their knowledge of how a bicycle works on a scale of 1 to 7. They were then asked to draw a bicycle from memory and explain its workings. Most of them got it wrong.
The global climate is certainly more complicated than a bicycle, which means that even fewer people know how that works. We do have computer models — so many that there is an international Program for Climate Model Diagnosis and Intercomparison (PCMDI). These models cannot simulate the actual physics of the earth-ocean-atmosphere system, because the physics takes place on small, short-duration scales, that give rise to changes that become apparent only on large, long-duration scales. There just isn’t enough computer power in the world to span the time and length scales from atoms to the entire world.
So, climate scientists make approximate sub-models with adjustable parameters to represent the gaps in their knowledge. The sub-models become components of a super-model that represents the earth’s climate. These climate models are being tested for their sensitivity to the parameters in their sub-models. If a model turns out to be very sensitive to a given parameter, then research is commissioned to narrow down the uncertainty in that parameter so that the model will be better “tuned” to reality. This tuning is still in progress.
In other words, nobody actually knows how the climate is going to respond to humanity’s burning of fossil fuels. If the earth were as simple as a greenhouse, it would get warmer by an easily predictable amount. On the other hand, all the models predict some amount of warming.
It would be prudent to reduce humanity’s burning of fossil fuels. The control freaks in society want to make fossil fuel energy artificially more expensive by so-called “cap and trade” legislation. This may allow current renewable energy technology to be more price competitive with fossil fuels, but it comes at the cost of making everyone on earth incrementally poorer. The poorest will probably die.
A better idea is to try to invent “greener” technologies that make energy so cheap that nobody can profit by bringing fossil fuels out of the ground. That will make everyone on earth incrementally richer. It will also disempower the world’s oil autocrats.
Must we employ draconian public policy measures to compel reductions in fossil fuel burning? Is it already too late to wait for the development of alternative energy technologies to make fossil fuels obsolete? Nobody knows.
Chabris, Christopher and Daniel Simons (2009). The Invisible Gorilla. New York: Broadway Paperbacks.