sexta-feira, 20 de abril de 2007

Climate Control, Beijing-Style

June 4, 2006




The rain in Spain stays mainly in the plain, but in China? Well, the government will decide.

The rainy season has come to northern China, and it’s a brave new world out there. Actually the natural rainy season doesn’t start until July. But the season of man-made rain is upon us, and Chinese rainmakers have been busy. Over the past month they've mobilized cloud-seeding aircraft, artillery and rockets to enhance rainfall. "We've ordered technicians to try to make it rain again today, but so far they haven’t reported back on the results," says Zhang Qiang, a businesslike woman who heads the Beijing Weather Modification Office (yes, that’s the official name of a real Chinese government agency). "We did it many times last week to increase the rainfall."

Not content with simply making it rain, now China's weather modifiers have taken on another meterological mission: to help guarantee perfect weather when Beijing hosts the Olympic Games in 2008. "In China, we haven’t done this type of thing on a very large scale yet," says Zhang during an interview in a west Beijing compound housing five antiaircraft guns used to shoot chemicals into the clouds. "The Russians have experience creating good weather, and we can learn something from them. We still have two more years for testing. I’m sure our preparations for the Games will go well."

Zhang's office, which employs 30 people, is part of the Beijing municipal government and the nationwide China Meteorological Administration. Her unit uses two aircraft and 20 artillery and rocket-launching bases to help modify weather around the city. Springtime is the busiest season for agricultural purposes. But more and more, Zhang and her colleagues are experimenting with weather modification to try to create blue skies. Toward this end, they’ve spent nearly a month and a half total researching the effects of certain chemical activators on different sizes of cloud formations and at different altitudes. Chinese meteorologists claim that similar efforts helped create good weather for a number of past VIP events in China, including the World Expo in Yunnan, the Asian Games in Shanghai and the Giant Panda Festival in Sichuan.

And why not? The central-government leadership—dominated by engineers—has been messing with Mother Nature ever since the Chinese Communist Party came to power. They’ve built the world’s biggest dam, the world’s highest railway and even the world’s biggest Ferris wheel (in Nanchang, still awaiting verification from the Guinness World Records). Why not perfect the science of climate control?

Well, um, there is the small political question of what happens to apparatchiks if they get it wrong. At least that’s what was on Zhang’s mind on Sept. 30, 1999, as Chinese leaders frenetically prepared for Beijing’s National Day celebration the following morning. Marking the 50th anniversary of the founding of the People’s Republic of China, Oct. 1 was slated to be a bash with a full-on military parade, goose-stepping militiawomen in red miniskirts and a flyover of aircraft and helicopters buzzing Chinese VIPs on the rostrum above Tiananmen Square.

But there was one problem: a storm system threatened to make it rain on Beijing’s parade. China’s rainmakers debated whether to induce a strong downpour just before the gala, increasing the chances of blue skies on the big day. “I was on duty,” recalls Zhang. “I intended to modify the weather by using artillery.”

But Zhang understandably fretted about Mother Nature’s unpredictability. “I worried that if the techniques I used weren’t good enough, there would be a big problem. I could make things even worse,” acknowledges Zhang, inferring that she could have lost her job. “So I didn’t dare do anything.” To everyone’s relief, the rain stopped of its own accord.


In the beginning, the idea was to improve harvests for Chinese farmers, who still comprise nearly three quarters of the nation’s 1.3 billion people. Chinese scientists began researching man-made rain in 1958, using chemicals such as silver iodide or dry ice to help produce condensation in moisture-laden clouds; such efforts can enhance rainfall during planting seasons or minimize the destructive effect of hail. Firefighting is another function; last autumn, authorities in northeast China induced artificial rain to assist 10,000 firefighters battling a massive forest fire in Heilongjiang province.

Today Chinese rainmakers are among the world’s busiest. Beijing's nationwide weather-modification budget exceeds $50 million a year. The communist regime’s 11th Five Year Plan, which kicked off this year, calls for the creation of 48 billion to 60 billion cubic meters of artificial rain annually (somewhere between 12 trillion to 16 trillion gallons of water). Beijing needs it. Right now is when fruit trees and crops need life-giving water; the parched North China plain has been stalked by drought since 1998. Normal precipitation is between 22 and 24 inches annually, says Zhang, but Beijing had only 18 inches last year. And drought continued around China’s capital city this spring, “so we’re increasing rainfall using our own means,” says Zhang. “But man-made efforts can’t solve the drought problem altogether; they can increase rainfall by only 10 to 15 percent.”

And tampering with Mother Nature has been known to backfire. Cloud-seeding shells and rockets have sometimes gone astray, damaging homes and injuring inhabitants. City dwellers have raised concerns about environmental pollution, though meteorologists insist the silver iodide is used in such tiny quantities that it brings no negative health consequences. And the rainmaking scramble became so intense in 2004 that five Henan province villages reportedly squabbled over “cloud theft” after they all seeded the clouds simultaneously but only one district received the lion’s share of rain.

Still, Chinese authorities have discovered weather micromanagement can bring psychological relief from heat and dust. In 2004, when Shanghai’s sweltering temperatures soared above 95 degrees in July, weather modifiers induced rain to break the heat wave and reduce demand on the city’s overstretched power grids. “Shanghai was the first city in China to use man-made rain to cool down temperatures,” boasted Yu Zhaoyu of the city’s Meteorological Bureau.

This spring Beijing suffered from unusually fierce dust storms, which swirl out of the Gobi desert each year and coat the capital in fine yellow grit. One day in April a monster dust storm dumped 300,000 tons of sand on Beijing, according to local media. The city was still shrouded in gritty powder when temperatures and pollution levels began rising a week ago. To dispel the haze, technicians of the Weather Modification Office fired rocket shells packed with cigarette-size sticks of silver iodide into the clouds. It worked. Beijing enjoyed its heaviest rainfall of the year, which helped “alleviate drought, add soil moisture and remove dust from the air for better air quality,” reported the official Xinhua news agency.

The idea of creating good weather received political support from China’s former party head Jiang Zemin after he attended a 2000 celebration in Russia marking the 55th anniversary of the end of World War II. Jiang was impressed when the Russians induced rain to successfully clear up clouds for the ceremony. “When he came back, Jiang said China should do the same thing,” says Zhang, “We’re trying our best to be ready for the Olympics. Already we’ve succeeded in clearing up small cloud formations.” Dissipating larger formations that cover hundreds or thousands of square miles remain a challenge, she says. At any rate, heavy rains typically aren’t so prevalent in August, the month when the 2008 Games are scheduled. So when the time comes, China’s weather modifiers may ironically get a little help from Mother Nature.

© 2007 Newsweek, Inc.





Source: http://www.msnbc.msn.com

Sem comentários: