The rain makers Posted on May 1st
Whether it is the Chinese firing weapons into the sky to make it rain, or the Thai government setting up a “royal rainmaking project”, the science of weather modification has always had a touch of the sci-fi about it. So it is perhaps little surprise that the effectiveness of such an eccentric area of research has always been a little foggy. Indeed, no matter how hard you try - say, through launching silver-iodide particles into clouds to make them rain - it’s hard to tell how influential you’re actually being as it might have happened anyway.
But now, one of the world’s leading weather experts thinks that the wind
surrounding weather modification is set to change. Roelof Bruintjes, of the
National Center for Atmospheric Research in Colorado, USA, believes that
weather-monitoring technology is so hot nowadays that science fiction may
soon become science fact. Speaking earlier this week, he said: “Now we
can measure clouds so well - even from the inside - we can get many more
answers as to what the effects of man-made intervention are, and separate
them from what would have happened naturally.
“For the first time, we can discover whether humans have changed
weather patterns. It’s a whole new opportunity. We are at the most exciting
time for weather modification in its history.”
Many of the world’s driest nations have dabbled in weather modification
since its first major lab breakthrough in 1949, when researchers at General
Electric in New York discovered that silver-iodide smoke caused the kind of
droplets in clouds to turn to ice, a process vital to rain formation. Since
then, however, experts came to the conclusion that the processes involved in
rain formation were just too complex.
But that hasn’t stopped many governments from trying. There are currently
150 weather-modification projects taking place in more than 40 countries. In
many of these, researchers are using trials in which some randomly chosen
clouds are “seeded” while others are not, and both groups are
monitored. Arlen Huggins of the Desert Research Institute in Nevada, USA, is
leading one of these studies in Australia’s Snowy Mountains, where the snow
pack has shrunk in recent decades. Reportedly, their results to date might
suggest that seeding works (although there are still two years of the
six-year project left to go).
The most extensive operations are taking place in China, however. Here, for
example, weather-modification “authorities” use conventional
military weaponry to bombard clouds with silver-iodide particles. Under the
guidance of the China Meteorological Administration (CMA), local “weather
changing” offices employ some 39,000 staff equipped with 7,113
anti-aircraft cannons, which, in 2006, were used to fire a million rounds of
silver iodide into the atmosphere (with the country spending over $100m a
year in the process). The Chinese state news agency claims that between 1999
and 2006, China produced 250 billion metric tonnes of artificial rain,
though researchers take this with a pinch of salt.
In the UK, Philip Brown, the Met Office’s cloud-physics research manager,
says: “There have been many experiments in the US; Israel had a
programme for a long time; and more recently, South Africa has done a lot of
work. I know it has been done in Switzerland and France, promoted in part by
insurance interests, to reduce damaging hail. The firms, which I’m sure
part-funded operations, were looking to decrease insurance losses on crop
damage. Russia has a semi-operation set up to do cloud seeding, too.”
So, what is prompting these gargantuan efforts? Brown explains: “On the
one hand, it’s the scientific intrigue of trying to understand what makes
clouds rain. And then there is the sometimes much more powerful economic
imperative. Clearly there are a lot of regions suffering - such as Australia
recently - with drought.
“People will try anything to avoid such things, even if the scientific
signs supporting it are a little weak. The potential economic value
outweighs the scientific values. Making it rain where it wouldn’t otherwise
might allow you to keep agriculture going.”
The Chinese have gone public with their intention to stop drizzle ruining
the opening ceremony of the 2008 Olympics. The government’s concern is that,
during the summer, there is a 50 per cent chance of rain. It has announced
that “action units” will “stand alert” upwind of the
city, ready to wring the clouds dry before they can drift over any stadium.
The initial response of some scientists - to pour scorn on such proposals -
may have been woefully misplaced, however, as for the first time, experts
may be able to see if the weather is affected by such schemes. Bruintjes
says: “We have seen that ‘changing clouds’ does work in certain
circumstances. But these often have to happen naturally, and we have to be
able to detect those conditions ahead of time. However, our models are
getting better and better at predicting this.”
His comments, likely to cause controversy, prompt the question: how much
money would have been saved if the flooding in Ireland and Britain last year
could have been avoided? And how many lives could have been saved (at least
1,300) in and around New Orleans if 2005’s Hurricane Katrina could have been
averted? Such issues will become increasingly pressing across the developing
world as the climate changes.
But some weather-watchers are concerned that weather alteration will lead to
accusations that governments are “playing God”: “Roelof is a
leading researcher in cloud physics, and very qualified to make some
statements. But ethics do come into it,” says Leonard Barrie, director
of the research department at the World Meteorological Organization in
Geneva. “All areas of weather modification are still very
controversial. Some people think that diverting water for irrigation creates
benefit at others’ expense. Just because someone at point A gets more water
doesn’t mean there won’t be problems for those at point B, downwind, who
might get less. Weather modification could cause similar problems.”
These are huge issues for the world’s economy, and companies may believe
that, even if it does prove costly to create a dry Wimbledon, say, or a
rainy crop season, it will be worth the effort. Wacky weather technologies
will doubtless be fizzing into the sky for another few decades yet.
Bring on the rain
A torrent of US-based schemes (and others worldwide) have tried to tinker
with the magic behind rain creation. They include the “Western Kansas
Weather Modification Program”, which is trying to cut the size of hail
or boost rainfall and snow. “What’s beginning to happen is that,
worldwide, people are realising that water, especially fresh water, is a
very precious resource, and we need to do what we can to increase its
availability,” said Bruce Boe, of Weather Modification Inc, a North
Dakota-based rainmaking company.
Make the sun shine
According to Russian media reports, that nation’s military has announced
that up to 12 aircraft will “disperse clouds” to “ensure good
weather” over Red Square during Victory Day celebrations in Moscow
early next month. Last year, the Russian Air Force claimed to have nixed
cloud formations by spraying them with potent concoctions including dry ice,
silver iodide and cement powder. Colonel Alexander Drobyshevsky said the Air
Force’s “most experienced crews” would be employed to guarantee
blue skies over the Kremlin.
Reduce smog
Ahead of this summer’s Beijing Olympics, the Chinese government hopes to
provoke showers, by injecting chemicals into clouds, to “wash away
pollutants”. The massive drive to reduce smog also includes the
planting of a forest twice the size of New York’s Central Park on a
1,750-acre site north of the Olympic village, to raise oxygen levels. Nearly
a dozen factories are closing or relocating outside Beijing, and the local
press speculates that factories hundreds of kilometres away will suspend
operations for the duration.
How to prevent storms
In February, Joe Golden, of the US Department of Homeland Security,
organised a meeting on hurricane modification. His ultimate aim? To look
into how researchers can banish these devastating tempests from American
skies for ever. “It’s time for a fresh look at hurricane modification,”
he said. Golden’s storm-destroying efforts will join those of Eastlund
Scientific Enterprises Corporation of Houston - which recently proposed
beaming microwaves into clouds to dissipate twisters. “The anticipated
result is minimum impact on overall weather without [tornadoes’] death and
destruction,” said a company spokesperson.
- Rob Sharp