Can Scientists REALLY Make (or Are It Rain They a Useless Shower?)
Byline: Michael Brooks
At the height of the Vietnam War, soldiers who heard US aircraft flying high over the Ho Chi Minh trail might have feared bombs were about to fall from the sky, or at least that reconnaissance pilots were taking pictures of the Viet Cong's supply lines. In fact, they had very little to fear. The planes were just trying to make it rain - but they weren't very good at it.
The idea was simple: seed the heavy clouds with tiny particles of silver iodide whose electrical charge would pull together the cloud's water droplets. Once enough droplets had gathered together, their weight would make them fall from the sky as rain. The resulting deluge would turn the Vietnamese supply lines into a quagmire and halt the communists in their tracks.
Operation Popeye started in 1966 and ran for seven years. Pilots flew 2,600 rain-seeding sorties, but it was a dismal failure. There was a little rain but not enough to halt the supply lines. And it might well have rained anyway, even without US intervention.
Fast-forward four decades and you'll find the same idea, and the same controversial result, is back in play. A Swiss company called Meteo Systems claims to have seeded more than 50 rainstorms over the Abu Dhabi desert last year. Some scientists have rubbished the claims. 'The Meteo Systems claims are really nothing more than that - it is a simple example of a chance outcome,' says Dr Deon Terblanche, a weather modification expert at the World Meteorological Organisation.
Others say they might be true. Meteo Systems uses a technology that is new to this field: a network of towers that use electricity to electrically charge the air. The ionised air then seeds rain.
Professor Peter Wilder, of the Technical University of Munich, did not see the rain fall in the desert but he is keeping an open mind about this new idea. 'I am convinced that the ionisation technology has the potential to work,' he says. Dr Terblanche is not. 'There is no scientific basis to this technology,' he argues.
So far, then, no one knows whether rain-seeding really does do what its supporters claim. Measuring the success of weather modification projects is like peering through a thick fog - and it always has been.
The American efforts in Vietnam were the culmination of a military project started by the mathematical genius behind the atomic bomb. John von Neumann had provided many of the essential calculations for designing the weapons that devastated Hiroshima and Nagasaki.
After the war, he turned his attention to making a weapon out of the weather. He gathered fellow scientists at Princeton University and formed a team that would investigate how to wage 'climatological warfare'. The main idea was to create a drought that would ruin Soviet grain harvests or floods that would devastate cities.
Though significant amounts of money were poured into this secret programme, it never achieved reliable results. And as information began to leak, the public became angry. Planes flying over South Dakota in a 1972 cloud-seeding experiment were even shot at by farmers. It didn't help the government's cause when the South Dakota experiment was followed by a devastating flood. The citizens of Rapid City sued the government after 238 people died when a year's worth of rain fell in the space of a few hours.
Britain has had its own Rapid Citytype disaster. On August 15, 1952, floods struck the town of Lynmouth, Devon, eventually killing 34 people and leaving more than 400 homeless. The RAF had been trying out some cloud-seeding in the region, but as with Rapid City, the Government didn't take responsibility. Lynmouth's rain, the Ministry of Defence said, was coming anyway.
Attempts to modify the weather are going on in around 40 countries now. China is the most gung-ho: the Beijing government employs around 50,000 people in various weather modification centres. …