On Chaos and Climate

Dear Watchers:
A response to Dick Conoboy about his “Climate Chaos, Tipping Points and The Final Buzzer” article in the January issue. It’s certainly a well-intended piece. And I thank him for it.

However, one problem is that it implies an overstatement of the chaos or butterfly effect.

That is, it’s quite true that because turbulence is chaotic and weather is known to be driven by synoptic scale eddies/jet stream, Hadley cells, trade winds, Kelvin and other kinds of waves, etc., that are in part turbulent, weather is thus known to be chaotic.

And this is why the better weather forecasts run their models multiple times, each with very slightly different initial conditions (that are within the range of uncertainty/precision of the weather observations made by satellites, buoys, weather stations, etc.) to create a probabilistic, ensemble picture that is usually more accurate than a single run.

So, a slight change in the assumed initial condition (a flap of a butterfly’s wings), may, over time, change the precise track and timing of a hurricane. But it’s a popular overstatement (using “quantum leap” to imply something very big, when it actually refers to something very small) to claim that an overlooked butterfly can create or dissipate a hurricane. There’s simply too much energy (typically, a thousand Hiroshima bombs worth) involved for that to happen.

That said, climate scientists also know that shorter term climate cycles like the El Nino/La Nina (ENSO) are chaotic. But because climate consists of averaging thousands to billions of weather events, and the longer and wider one averages, the more transient noise and chaos effects get smoothed away, there’s no real evidence that longer term climate events are chaotic. Ergo, I’m quite certain that almost all real climate scientists would not say that global warming, for example, is chaotically driven. To be blunt, it’s man-made and reasonably predictable.

Though I’ve done some research on chaos as applied to atmospheric turbulence, don’t take my word for it. Instead, I suggest you take a look at http://www.realclimate.org/, which you’ll find is really sort of a watering hole for some truly eminent climate scientists — people who together have published thousands of some of the best papers in climate science. And though they don’t all agree on some details, they have quite a bit to say about the topic of chaos and climate. I’d pay particular attention to any comments by Ray Pierrehumbert.

Real Climate: Butterfly Effect

Ray Kamada