The Blog


12:00 AM, Aug 5, 1996 • By ERIC FELTEN
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THE GLOBAL WARMING DEBATE is in a rut. In mid-July, for example, Undersecretary of State Timothy Wirth called for a crackdown on the emission of so-called greenhouse gases that are the inescapable byproduct of burning coal and oil. Any effort to choke off carbon-dioxide emissions will hit the American economy hard; nonetheless, to the dismay of industry, Wirth has in mind new, binding treaties to do just that. "The science calls on us to take urgent action," Wirth declared at a Geneva conference on climate change. Industry -- as represented by the Global Climate Coalition -- responded as expected, arguing that the science is hopelessly complex and muddled: We should wait and see instead of doing anything rash and ruinously expensive.

This is the stale and predictable state of the global warming debate. Environmental Cassandras declare the world is on fire; naysayers say nay. Greens use elaborate computer models to show that the atmosphere is working its way from a simmer to a full rolling boil. Industry chooses different computer models and finds that global temperatures are the same as they ever were. The scientists can't agree and the layman is understandably bewildered.

But there might be a way out of this tiresome political shuttlecock. The one thing that the Cassandras and the naysayers seem to agree about is that there is only one solution to global warming -- reduce the amount of greenhouse gases put into the atmosphere. But what if that assumption is incorrect? A surprising, and surprisingly large, body of scientific research suggests that it may be entirely possible (and even relatively inexpensive) to cool the planet down, greenhouse gases or no. The whole premise of the greenhouse theory is that human activity is capable of turning the global thermostat up. If so, then why shouldn't human activity be capable of doing the reverse?

Early this year, the east coast buried in snow, newspapers and newsmagazines declared perversely that the blizzards were the fault of global warming. Shifts in worldwide climates caused the extreme weather, we were told. These stories did point to some evidence of a greenhouse effect: 1995 was the hottest year on record, breaking the mark set in 1991. But little noticed was the fact that between 1991 and 1995 temperatures had not just held steady, they had declined dramatically. And climatologists do agree on the reason temperatures spiked downward for a few years: a volcano. When Mount Pinatubo erupted in 1991 it belched tons of dust, ash, and sulfur into the stratosphere, where the fine haze of debris floated for a couple of years, ever so slightly shading the earth from the sun. Which raises the question, It dust in the stratosphere can cool the planet, why not combat global warming by putting dust in the stratosphere?

There are any number of tidy, discreet, and costeffective ways to get dust or sulfur into the upper atmosphere. A variety of options can be found in a massive 1992 tome from the National Academy of Sciences called "Policy Implications of Greenhouse Warming." Chapter 28 is devoted to what is called " geoengineering," the science of purposefully making large-scale changes to the environment. Not only are an abundance of atmospheric fixes considered in the chapter, but careful cost breakdowns are provided for each.

Among the suggested methods for launching dust into the stratosphere are rockets, balloons, airplanes, and naval guns. Naval guns are among the cheapest, and certainly the most dramatic. According to the National Academy, "A 16-inch naval rifle fired vertically could put a shell weighing about 1 [metric] ton up to an altitude of 20 kilometers." After running the numbers -- including the cost of using the Navy ships and crew, the price of shells, and even the going rate for bulk dust -- the National Academy found that it would cost somewhere between three cents and $ 1 to offset the effect of one metric ton of carbon-dioxide emissions. Mitigating the amount of carbon dioxide put into the atmosphere by the United States in 1989, given these estimates, would cost, tops, about $ 500 million a year, and probably a lot less.