Tuesday, May 4, 2004

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The Asian brown cloud

The Chicago Tribune's front-pager yesterday was a James P. Miller story about the effect of Chinese air pollution -- the "Asian brown cloud" -- on U.S. weather. Some of the tidbits:

Add one more item to the long list of things Asia exports to the United States: air pollution.

The contaminated air that rides the jet stream to Trinidad is laced with the sulfates and soot from Asia's industrial smokestacks, and nitrogen oxides that emerge from tailpipes of Asia's rapidly growing fleet of automobiles. It contains particles from fires set to clear jungles for farming, and from the millions of households that burn coal, wood or animal dung for heating and cooking.

Scientists identified the phenomenon five years ago. The Asian brown cloud, researchers now know, routinely climbs high enough into the atmosphere to hitch a ride on the fast-moving jet stream heading east to North America. In April and May, when seasonal winds are strongest, the high-altitude pollution can cross the Pacific in as little as four days....

So far, the increase in ground-level pollution that the Asian brown cloud causes in the United States is "not catastrophic, or even critical," said David Parrish, a research chemist with the National Oceanic and Atmospheric Administration's Aeronomy Lab in Boulder, Colorado....

A cloud heavy with particles of dust or pollution is whiter than a non-polluted cloud, because water droplets condense around the particles, explained [scientist V.] Ramanathan.

"Double the aerosols, double the droplets," he said. That means polluted clouds reflect sunlight more efficiently than a clean cloud. And that, in turn, affects the weather.

When clouds scatter sunlight, ground-level temperature declines. Such unnaturally high reflectivity also can suppress rainfall, or it can hold rain back so long that when it finally does fall to earth, it comes in the form of a damaging downpour, said Ramanathan.

Some researchers, in fact, think the extra-white clouds caused by dirty air are helping to offset the global warming effect. That would offer an explanation for the unsettling fact that "the planet hasn't warmed as much as the models suggest it should," given the amount of greenhouse gas that humans have released into the atmosphere, the researcher said.

The Asian cloud is only the first and largest of a number of high-atmosphere brown clouds scientists have discovered. This summer, National Oceanic and Atmospheric Administration is funding a major study of a similar blotch found hovering a mile or more above the eastern U.S. (and which sends a plume of dirty air trailing toward Europe.)

It's not clear if there are any policy implications from this -- but I hadn't seen the phenomenon reported previously.

posted by Dan on 05.04.04 at 12:28 AM


you mean some kind of kyoto protocol? :D the thing tho is that they're just going to do what's in their national self-interest, so if it doesn't affect them as much, why bother regulating it? that's why the US never signed on! until convinced otherwise it's always 'best' to offload externalities on others, esp if you profit from it.

so, ironically, it's not global warming per se that gets people to act, but los angeles warming, alaska warming and colorado warming, even if the causation is still somewhat sketchy. there's nothing like an 'asian brown cloud' to awaken primordial fears of a 'yellow peril' threatening the states to make headlines.

posted by: chosun on 05.04.04 at 12:28 AM [permalink]

There is a lot of supposition in that article. Even if it is taken on faith, my solution would be to speed the process of China's advance so that it doesn't have to rely on old tech. Fears of an 'Asian Brown Cloud' (what a great name) don't help anything; and the discussion about the 'whiteness' of clouds? Are these scientists or highschool science teachers?

posted by: Scott on 05.04.04 at 12:28 AM [permalink]

"That would offer an explanation for the unsettling fact that "the planet hasn't warmed as much as the models suggest it should," given the amount of greenhouse gas that humans have released into the atmosphere, the researcher said." First off, why is it unsettling? Don't we want less warning. Second, if the models are off, it is more likely that the very blunt instrument of computer modeling is just not accurate, not that there must be some other natural explanation.

posted by: Kyle Swanson on 05.04.04 at 12:28 AM [permalink]

"Such unnaturally high reflectivity also can suppress rainfall"

I wonder if that's a factor in the drought in the southwest US.

posted by: Jon H on 05.04.04 at 12:28 AM [permalink]

Yet another reason to celebrate high oil prices today, which (don't economists tell us this?) should drive down consumption and stimulate research into alternative energy sources.

posted by: General Glut on 05.04.04 at 12:28 AM [permalink]

Scaring people generates funding, votes, etc. So scientists will do it. So, yeah, the scientists are trying to spin this as a reason (externalities) that global rules for emissions are necessary.

However, this has absolutely no connection to the Kyoto Protocol. First of all, these types of pollutants are of the sort not regulated by Kyoto at all, which only covered CO_2. These are things like SO_X, and NO_X, etc., which are already heavily regulated in the US, and whose US emissions have and continue to be decreasing. Adopt Kyoto or not, and there would be no effect on these. (Well, unless we all switched to diesel to decrease CO_2, which would at the same time emit MORE formaldehyde, NOX and SOX.)

Even beyond that, of course the PRC was not required to make any cuts under Kyoto anyway. In the case of 朝鮮 (or 韓国 if you like), I'm not sure what cuts were required. Given the ROK's alternating habit of insisting that it's wealthy (when it wants to brag) and that it's a developing nation (when it wants to defend its way-more-outrageous-than-the-US-or-Europe farm subsidies), I wouldn't be surprised if it was mostly off the hook.

posted by: John Thacker on 05.04.04 at 12:28 AM [permalink]

"That would offer an explanation for the unsettling fact that "the planet hasn't warmed as much as the models suggest it should," "

Only in the environmentalist cult does this statement make any sense.

Isnt the scientific method to form a hypothesis, test it, revise the hypothesis? When did that turn into: form a hypothesis, test it, when tests consistantly contradict hypothesis look for other mechanism masking the underlying intergrity of the hypothesis? Preferably of Asian design?
Occam is spinning on his razor.

posted by: Mark Buehner on 05.04.04 at 12:28 AM [permalink]

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