From the archive, originally posted by: [ spectre ]

China Asks Rainmakers for Blue Sky at Olympics
By Mure Dickie in Beijing

Published: June 17 2006

When a sandstorm dumped an estimated 300,000 tonnes of dust on Beijing
in April, the local arm of the world’s largest rainmaking operation
swung into action.

Workers sent by municipal meteorologists scaled hills around the
capital and burned silver iodide from their peaks in an effort to clean
the air by coaxing rain from the grit-filled skies.

But coping with sandstorms is far from the only role played by China’s
37,000 full and part-time rainmakers, says Wang Guanghe, the director
of the Chinese Academy of Meteorological Sciences’ institute of weather

Experts on artificial precipitation across China use about 30 aircraft,
4,000 rocket launchers and more than 7,000 artillery pieces to ease
droughts, cool overheated cities, prevent damaging hailstorms, put out
forest fires and replenish riverheads. And with the Beijing 2008
Olympics fast approaching, the weather changers have a new
responsibility: ensuring a rain-free games.

“The Beijing city government is very concerned about the weather for
the Olympics ,” says Prof Wang in an interview immediately followed by
an apparently serendipitous June shower. “There is a plan to undertake
rain-prevention work, particularly if there is [threatening] weather
for the opening and closing ceremonies.”

Officials are convinced of the merits of weather modification in a
nation troubled by chronic water shortages in its arid north. The state
Xinhua news agency this month reported that rainmaking aircraft alone
had in the past five years “undertaken enough missions to fill four
Yellow Rivers”.

The National Meteorological Bureau’s latest five-year plan includes an
expansion of the weather-modification system intended to “achieve an
annual increase in rain of around 50bn cubic metres”.

What is less obvious, however, is whether the efforts, expense and
occasional accidents involved are justified. The technology behind most
rainmaking is well-established: aircraft, rockets, artillery shells or
hill-top burners are used to “seed” clouds with silver iodide particles
around which moisture can collect and become heavy enough to fall.
Advocates say they can induce rain from clouds that might otherwise
either dissipate or grow to a scale that might threaten a sporting
event. But cloud-seeding has in the past been likened by sceptics to
more primitive approaches to weather modification, such as rain dances.

Prof Wang accepts that it remains notoriously difficult to establish
how much impact cloud-seeding has, since there is no way to be sure how
much rain might have fallen without intervention. However, he says
research in south-eastern Fujian province suggested cloud-seeding
resulted in 23 per cent extra rain.

But even ardent proponents acknowledge that it can never be a panacea
for problems such as drought in northern China. Officials should also
not rely too much on technology to prevent any presumptuous
precipitation from dampening Olympic spirits in 2008.

Heavy rain is relatively unusual for Beijing in August, and the bigger
challenges are likely to be the summer heat and polluted air. But Prof
Wang says he “would not dare” to promise a dry games, noting that
Beijing’s weather-changers may be able to dispel light showers but
would struggle if a downpour threatened at the wrong time.