“Cloud Whitening” And The Hubris Of Science

I know that people disagree about the science and causes of “global warming,” but can we all agree that having scientists engage in large-scale environmental science experiments is not a great idea?

Consider the proposal to engage in “cloud whitening.”  Humans would spray fine droplets of sea water into the air.  The theory is that water vapor would condense around the salt crystals, producing new clouds or making existing clouds thicker and therefore “whiter.”  Whiter clouds reflect more solar energy back into space than does cloudless sky, so creating more, larger, and whiter clouds should reflect even more solar energy back into space, cooling the Earth.  The theory hasn’t been tested.  Nevertheless, many scientists apparently have seized on “cloud whitening” as a quick way to make a dent in global warming trends.

Now a scientist has announced results of a study that raises some significant cautionary issues about the concept of “cloud whitening.” Her study concludes that lots more salt would need to be sprayed than first thought, and that if we don’t get the size of the particles precisely right we could reduce cloud cover rather than increase it — and thereby increase the warming effect of solar energy.

I don’t know who will ultimately decide whether humanity should engage in some of the large-scale environmental engineering projects that periodically are proposed by scientists — but I hope it is someone with a healthy skepticism about the certainty of science and some humility about the ability of humans to confidently predict the results of their efforts on something as complex as the Earth’s weather systems.  We get all kinds of assurances from scientists and engineers, and sometimes they are wrong.  It’s one thing when they screw up a machine or a theory about how gravity works.  It’s quite another if their tinkering wrecks weather patterns and unintentionally turns Iowa into the Midwestern version of the Sahara Desert.