Soot clouds over Islam

Note: I had to bury this, but wanted it on the blog, so I just replaced an older article I never published.

CARL SAGAN RICHARD TURCO 1991 New Perspectives Quarterly

ITHACA, N.Y. - Oil is not only a chief cause of the war, not only fuel for the machinery of war, but also now a weapon of war. Now a vast oil spill, the largest in human history, is spreading through the Persian Gulf, threatening the ecology and desalinization plants of Saudi Arabia and the Emirates.

Before the war is over, pollution of this sort may attain a still more unprecedented scale. But there is a military use of oil that is still more ominous: massive injection of soot into the atmosphere. In the fall of 1990 Iraq announced that, under some unspecified circumstances, it was prepared to set fire to all 363 productive oil wells in Kuwait.

On Jan. 22, 1991, U.S. reconnaissance satellites detected plumes of dark, sooty smoke erupting from several refineries and wells in Iraqi-occupied Kuwait - perhaps a harbinger of the promised full conflagration. The smoke rose and was carried by the winds across the Persian Gulf to Iran, where some of it fell to the ground as "black rain. " The rest continued moving eastward.

What would happen if there were extensive petroleum fires in the war zone? Kuwaiti oil wells are, of course, not the only possible sources of soot. There are also wells, refineries and petroleum storage depots to burn in Iraq - some of which were reportedly on fire because of military action of the coalition allies - in Saudi Arabia, the other gulf Emirates and, if the war expands and old scores are settled, in Iran.

There is stored oil in ports, ships and pipelines. There are natural gas wells. And, of course, there are cities. We have calculated what might happen if only the active oil wells in Kuwait burned.

Smoke would be blown by the prevailing westerlies over Iran, Afghanistan, Pakistan, India, Bangladesh, Southeast Asia and South China. The higher the smoke rises, the further east it is blown before it falls out or is rained out of the atmosphere.

Soot is very close to the darkest material known in nature.

Fine particles of soot absorb sunlight, warm up, and heat the surrounding air, which then expands and rises, carrying the suspended soot with it. This ability of soot to pull itself up is called self-lofting. It is predicted by the physics of the problem and has been demonstrated in experimental fires. As a result, there are plausible circumstances in which the soot from Kuwaiti fires would rise many kilometers into the air and be carried great distances across South Asia.

Capping an oil-well fire is a risky and difficult business. It takes the best teams in the world (and there are very few of them) a week to several weeks to do it. Quickly capping 363 oil well fires in a war zone is impossible.

The fires would burn out of control until they put themselves out. This, it is thought, would take months, and perhaps as long as a year. So, if these fires were set in winter, say, they might continue to burn through spring and summer at least. This is the growing season for many crops.

Soot would pour into the air at a certain rate and fall or be rained out of the air at a certain rate. The resulting steady-state amount of soot might well stretch over all of South Asia. In some circumstances, it could be carried around the world. Perhaps as much as 20 to 40 percent of the Northern Hemisphere might be covered by the pall.

Even if it only covered South Asia, the consequences could be dire. Beneath such a pall sunlight would be dimmed, temperatures lowered and droughts more frequent. Spring and summer frosts may be expected.

Agriculture is vulnerable. One night of below-freezing temperatures is enough to destroy the Asian rice crop. A temperature decline of only 3 or 4 degrees Celsius can destroy the Canadian and U.S. Midwest grain crop.

A real-world example can be found in the aftermath of the explosion of Mt. Tambora, an Indonesian volcano, in 1815. The two cases are not the same: Tambora injected a very large quantity of fine transparent particles into the stratosphere; Kuwaiti fires at their worst would inject much smaller amounts of much darker particles, but not to as high an altitude. However, the amount of sunlight that got through the Tambora cloud (which covered much of the Northern Hemisphere) and what we calculate from a massive Kuwaiti oil-fire pall are about the same.

The year 1816 was known variously as "the year without a summer," "poverty winter," "the year of the beggars," and in New England, "eighteen hundred-and-froze-to-death. " Traditional military wisdom holds that even remote contingencies must be taken into account if their consequences are serious enough. Since many of the nations most in danger are Islamic, perhaps Iraqi war planners might wish to reconsider torching the Kuwaiti oil fields - even as a gesture of defiance.

And coalition forces may want to avoid targeting large numbers of petroleum and natural gas facilities in Iraq.

Not only is the Gulf War being fought at least in part over oil - with more than a million uniformed young men and women from some 30 nations at risk because of it. The use of oil as a weapon can put vast numbers of civilians at risk. Add to this the pervasive local and regional pollution from the routine peacetime use of fossil fuels, and the extremely serious long-term danger of global warming from the same cause, as well as the risky dependence on foreign imports of oil, and it is reasonable to ask whether there are any alternatives.

Wouldn't many of the problems before us be avoided or mitigated if there were other energy sources we could use?

Nuclear reactors have, especially after Chernobyl, a wide range of real and perceived problems. But a world energy economy run substantially off solar energy and hydrogen fuel, for example, would generate no soot, no greenhouse gases, no local pollution and could hardly serve as a cause of war: sunlight is a widely available commodity.

These and many other technologies, more than competitive with oil when all costs are added in, could be developed.

But the U.S. government spends less on developing such alternative technologies in a year than the Gulf War costs in an hour.

With a slight adjustment of priorities, opportunities for the development of new industries would be immense. One lesson of the Gulf War, evident even at this early stage, is the need for industrialized nations to begin phasing out the world petroleum economy and phasing in cheaper, cleaner, safer alternatives.

Carl Sagan of Cornell University is a Pulitzer Prize-winning scientist and creator of the "Cosmos" public television series.

Richard Turco of the University of California-Los Angeles is a recipient of the McArthur Prize Fellowship.