Fans of Kurt Vonnegut might know that it was the novelist's brother, Bernard, who in 1946 discovered that seeding clouds with silver iodide could bring on rain. The idea was never put into wide use in the U.S., but China has been playing God since the late 1950s. Today, the government's Weather Modification Office maintains a network of thousands of peasants and farmers who regularly fire anti-aircraft guns loaded with silver iodide into the sky whenever and wherever the WMO decides it should rain. This system is expected to be in full-scale use during the Olympics to help avoid such embarrassments as having the opening ceremonies rained out or a high-profile foreign athlete collapse in a fog of noxious Beijing air.
Schemes to control the weather on a global scale are relatively new, however. With the Arctic ice cap disappearing at an alarming rate, not-so-mad scientists have begun to talk openly about geo-engineering-using technology to manipulate Earth's climate to help mitigate the ravages of global warming.
Most of the interest in geo-engineering circles is focused on finding a way to simulate one of the Earth's most effective natural cooling methods: the volcano. In 1991, the world got a taste of how this kind of climate-tinkering might work. That's when Mount Pinatubo in the Philippines erupted in the largest volcanic blast the world had seen in more than a century, releasing roughly 20 million tons of sulphur dioxide into the atmosphere. The resulting layer of sulphuric acid haze reflected enough of the sun's energy back into space to cause a significant drop in global temperatures-an effect that lasted for about two years.
Scientists first proposed the idea of replicating a volcanic eruption to curb global warming way back in 1965, in a report on climate change prepared for U.S. president Lyndon Johnson. The idea didn't gain much momentum until a few years ago, when research conducted by Dutch chemist and Nobel-winner Paul Crutzen, perhaps the world's most respected climate scientist, lent the idea new credence.
Crutzen's plan calls for sulphate particles to be carried aloft using planes or balloons, and then pumped directly into the upper atmosphere. The cooling effect would be quick, with temperatures dropping in a matter of months. Although this would be a cheap solution, there are downsides: The sulphates would eventually fall out of the sky as acid rain, and the process could also damage the ozone layer. David Keith, a respected climate scientist at the University of Calgary, thinks he has the answer: floating tiny metallic disks above the ozone layer, applying a phenomenon known as photophoretic levitation. Keith's proposal, while more expensive, has an upside: Since the disks levitate, they wouldn't have to be replaced as often as sulphates, and the process wouldn't harm the ozone. There's an even easier, quicker way to cool the planet, according to Roger Angel, an astronomer at the University of Arizona. He suggests launching millions of small, reflective spaceships into orbit between the sun and Earth, blocking out 1.8% of the sun's energy. Quick and easy, perhaps, but insanely expensive-Angel admits it could cost trillions of dollars.
Not surprisingly, all of these schemes have critics in the scientific community. For one thing, the Earth's climate is an unbelievably complex system, and any futzing with it could have unintended-possibly disastrous-consequences. That's why no legitimate scientist currently advocates geo-engineering as a serious alternative to reducing greenhouse-gas emissions. Even Crutzen stresses that his sulphate plan is only meant as an absolute last resort, not as a quick fix.
Politicians in the U.S. and Canada-the world's two top polluters per capita-will no doubt pretend not to have heard that last bit. Clearly, something must be done about climate change-not even George Bush or Stephen Harper can deny that. But slashing carbon dioxide emissions means taking on major culprits like the automotive and oil-and-gas industries (which contribute an estimated $20 billion and $40 billion, respectively, to the Canadian economy), not to mention China, India and other up-and-coming polluters worldwide.
It also means spending a lot of money, although the details of just how much are sketchy. Trying to estimate the economic costs of climate change is controversial-standard models simply aren't equipped to deal with potential catastrophes of this magnitude. The most extensive study to date was produced in 2006 for the British government by Sir Nicholas Stern, the former chief economist of the World Bank. The main conclusion of his 700-page report: If we take no action on climate change, it could cost the world as much as 20% of its future GDP. If we act now, the price tag would drop to about 1% of current GDP-roughly $480 billion, or about the same amount the U.S. has spent fighting the war in Iraq.
But who's going to foot the bill? So far, none of the world's top polluters have volunteered to absorb the cost of cutting emissions. And if the freak storms, glacial melts and widespread droughts continue at the rate they're going, geo-engineering might well prove to be our only option, not to mention the precursor of even more tension in the world community. Imagine the scenario that might unfold if scientists actually did find a feasible way of controlling the climate, one that is as easy as adjusting a thermostat. Who would get to decide where to set it? Homes have broken apart over a degree or two. Think about that sort of conflict on a global scale, and suddenly $480 billion doesn't seem so bad.