The climate is a tera-watt scale planetary sized heat engine, not a high school experiment

Watts Up With That? shows why climate change is not just 'simple physics': I keep reading statements in various places about how it is indisputable “simple physics” that if we increase amount of atmospheric CO2, it will inevitably warm the planet. Here’s a typical example: In the hyperbolic language that has infested the debate, researchers have been accused of everything from ditching the scientific method to participating in a vast conspiracy. But the basic concepts of the greenhouse effect is a matter of simple physics and chemistry, and have been part of the scientific dialog for roughly a century. Here’s another: The important thing is that we know how greenhouse gases affect climate. It has even been predicted hundred years ago by Arrhenius. It is simple physics. Unfortunately, while the physics is simple, the climate is far from simple. It is one of the more complex systems that we have ever studied. The climate is a tera-watt scale planetary sized heat engine. It is driven by both terrestrial and extra-terrestrial forcings, a number of which are unknown, and many of which are poorly understood and/or difficult to measure. It is inherently chaotic and turbulent, two conditions for which we have few mathematical tools. The climate is comprised of five major subsystems — atmosphere, ocean, cryosphere, lithosphere, and biosphere. All of these subsystems are imperfectly understood. Each of these subsystems has its own known and unknown internal and external forcings, feedbacks, resonances, and cyclical variations. In addition, each subsystem affects all of the other subsystems through a variety of known and unknown forcings and feedbacks. Then there is the problem of scale. Climate has crucially important processes at physical scales from the molecular to the planetary, and at temporal scales from milliseconds to millennia. As a result of this almost unimaginable complexity, simple physics is simply inadequate to predict the effect of a change in one of the hundreds and hundreds of things that affect the climate. I will give two examples of why “simple physics” doesn’t work with the climate — a river, and a block of steel. I’ll start with a thought experiment with the block of steel.

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