gregory_benford's picture
Emeritus Professor of Physics and Astronomy, UC-Irvine; Novelist, The Berlin Project
Physicist, UC Irvine; Author, Deep Time

Save The Arctic

No one truly thinks we can slow global climate change within half a century; at least, no economist who has looked at the huge momentum of energy demand in the developing countries.

So: despair? Not at all. Certainly we should accept the possibility that anthropogenic carbon emissions could trigger a climactic tripping point, such as interruption of the gulf stream in the Atlantic. But rather than urging only an all out effort to shrink the human atmospheric-carbon footprint, my collaborators and I propose relatively low tech and low expense experiments at changing the climate on purpose instead of by mistake.

If we understand climate well enough to predict that global warming will be a problem, then we understand it well enough to address the problem by direct means.

Perhaps the simplest idea uses the suspension of tiny, harmless particles (less than one micron) at about 80,000 feet altitude, in the stratosphere.

A first test could be over the arctic, since the warming there is considerable. The polar bears need hjelp right now, not when we might get control of emissions, out beyond 2050. The Arctic atmospheric circulation patterns tend to confine the deployed particles, sweeping them around the pole but not southward.

One could use enough of the tiny particles to create a readily measurable shielding effect. An initial experiment could occur north of 70 degrees latitude, over the Arctic Sea and outside national boundaries. The particles would reflect UV rays back into space. They would reduce warming and stop the harm of UV rays to plants and animals. Robust photosynthesis would still occur, fueled by the visible spectrum.

This idea exploits our expanding understanding of the climate system, plus our knowledge that the marked cooling by volcanoes in the last century arose from sulphate aerosols at high altitude.

If this works, it could arrest Arctic warming and reverse the loss of sea ice. Since few live there, any side effects on people would be minor. By placing the particles at a high altitude, we can arrange for the first experiments to end when they rain out into the sea, perhaps after the Arctic summer has passed.

We could then put this particulate shield and other technologies on the shelf quickly and cheaply. They would be ready for use if the global environment worsens, signals that the scarier scenarios of a warming climate might be threatening.

Costs seem attainable—perhaps ten million dollars for a first experiment. Trials over open ocean are little constrained by law or treaty, so show-stopper politics may be avoided. "No Environmental Impact Statement Required" should be the goal.

We hope that a favorable experiment could change the terms of the global warming debate for the better. We must think of other methods of trimming the effects of warming, not just a War on Carbon that will take a century to win. As economist Robert Samuelson recently said, "The trouble with the global warming debate is that it has become a moral crusade when it's really an engineering problem. The inconvenient truth is that if we don't solve the engineering problem, we're helpless."