Chinese cloud busters dampen Shanghai heatwave

THE Chinese city of Shanghai yesterday said it had successfully induced rain showers by firing chemicals into clouds, breaking a heatwave that has severely strained electricity supplies.

Rain fell on Tuesday afternoon after a plane shot more than 400 pounds of silver iodide into clouds, according to a statement.

Those showers sparked natural storms that soaked large parts of the city with about half an inch of rain.

The cooling effect was immediate: yesterday’s high temperature was 31 degrees Celsius (88F), down from around 35 degrees (95F) in recent days.

Weeks of blazing temperatures have worsened an expected electricity deficit of about four million kilowatts in Shanghai, forcing power rationing on thousands of factories.

Shanghai had budgeted €600,000 for cloud seeding, storing 3,000 silver iodide shells at a military airport in nearby Wuxi.

While China is a world leader in cloud-seeding, the process evokes mixed reaction When rare clouds appear over often-parched agricultural regions, workers at the local weather bureau routinely roll out anti-aircraft guns and blast away at the sky.

The shells that explode contain fine particles of silver iodide which scatter through the moisture-laden clouds. If all goes well, a rainstorm occurs.

In the Northern Plains region, the heartland of Chinese agriculture, drought is an ever-looming threat. So farmers praise the weather bureau’s rainmakers as local heroes.

But as in the days of yore, when legend says that emperors ordered underlings to toss virgin girls into rivers to please the water dragon and unleash rainstorms, the quest for rain carries with it the threat of tempest. Some local officials now grumble that upwind neighbours unfairly intercept clouds for seeding, depriving downwind areas of rainfall.

Moreover, recent heavy rains and floods across China have raised questions about whether fiddling with weather can bring calamity as well as fortune.

“The technique is not perfect. There are many scientific problems,” said Hu Zhijin, an adviser to the Institute of Weather Modification in Beijing.

Nonetheless, China spent about €40 million nationwide on cloud-seeding efforts last year. Some 35,000 people took part in rainmaking efforts, employing 6,929 anti-aircraft guns and 3,804 rocket and artillery launchers to fire chemicals into the clouds.

There are many reports of serious side effects to the process, notably a BBC report in 2001 which claimed that 35 deaths in the Lynmouth flood disaster came only days after RAF rain-making experiments over southern England.

Ninety million tonnes of water swept down the narrow valley into Lynmouth on 15 August, 1952, destroying whole buildings.