Plan B for global warming

There’s a drawing of Don Quixote tacked to the wall of David Keith’s University of Calgary office; one of Gustave Doré’s famous illustrations showing the aging knight flying backwards off his horse as his lance bends against the blade of a windmill. The 45-year-old environmental scientist purchased it as a self-mocking reward after the publication of his 2004 paper, “The influence of large-scale wind power on global climate.” Using computer modelling, Keith and his colleagues posited that wind energy might not be quite as green as envisioned, potentially changing climate on a worldwide scale as fields of turbines slow the winds, changing rainfall and the amount of moisture in the soil. Their conclusion that the much-touted benefits from wind farms might actually be outweighed by the costs didn’t meet with broad public approval. Keith’s email inbox quickly filled with hate messages, a rare trick for an academic.

Should the trend hold, the professor might want to start clearing space on his wall for a crucifix. The work Keith is engaged in now messes with nature itself, breaking some of the greatest taboos of the world’s environmental movement. Spurred by new data suggesting global warming is progressing faster, and at a much more profound level than even the worst-case scenarios, he is at the fore of a small group of scientists proposing a quick technological fix: a “Plan B” to slow climate change and cool the earth almost overnight via massive human interventions. Among their science-fiction-style ideas: the deployment of millions of lenses the size of doughnuts in geo-stationary orbit between the earth and the sun, the creation of vast banks of artificial clouds over the world’s oceans, covering deserts with reflective material, and Keith’s preferred solution—seeding the stratosphere with sulphate or other particles. All schemes designed to send a portion of the sun’s rays back into the cosmos, and buy politicians, business and the public time to finally get serious about cutting greenhouse gas emissions.

When Keith first took an interest in such ideas—lumped together under the broad rubric “geoengineering”—as a grad student 20 years ago, they could hardly be discussed in polite scientific company. Even less so in environmental circles, where many viewed any proposal to manage climate change as a threat to efforts to stop it. “It was a freak show,” he recalls. Verboten in mainstream forums, the topic was only debated at secret NASA and White House-organized confabs.

But somewhere amid reports of melting icefields, worsening droughts, and soaring CO2 concentrations, previously closed minds snapped open. In the last two years, geoengineering has gone from the implausible purview of Dr. Evil-style kooks to a subject of serious scientific and political debate. In the U.K., the Royal Society, the country’s de facto academy of science, has launched a major study (Keith is on the panel) and a parliamentary committee is preparing a report. In the U.S., the National Academy of Sciences is planning a similar probe. Last week, President Barack Obama’s chief science adviser, John Holdren, revealed the administration has been discussing the options, with a focus on scattering—perhaps by plane, balloon, giant floating chimneys, or even artillery fire—massive quantities of sulphates or other aerosols in the upper atmosphere.

The idea is to mimic the effect of massive volcanic eruptions like Mount Pinatubo, which lowered global temperatures by 0.5° C after spewing out 18 million tonnes of SO2 in 1991. But what he didn’t mention should be of particular concern to Canadians. The logical lab for such experiments—100,000 tanker plane flights a year per one estimate—would be the Arctic, where the cooling would be of the greatest benefit, restoring sea ice and turning down the global thermostat.

Look at the eccentric history of geoengineering over the past two decades and Keith is there every step of the way. But now, with the research money about to start flowing, he worries things are maybe moving a little too fast. In late January, a joint Indian-German expedition defied a United Nations ban and dumped 20 tonnes of iron sulphate particles off Antarctica in hopes of fertilizing the growth of CO2-eating plankton. It failed—schools of hungry shrimp ate the plankton blooms.

And that’s the basic problem with geoengineering: no one is quite sure what happens “downstream” when you start messing with bits and pieces of the global climate. Would a colder Arctic mean more or less rain in the tropics? If you dissolved more CO2 in the seas, how would that effect marine life? Would the ecosystem be able to handle all that extra sulphur in the atmosphere? The cure could very well end up being worse than the disease.

“I have mixed feelings about it,” says Keith. “I think there are a lot of ways to manipulate the system, and when you start thinking about them, you just come up with more and more.” He clicks through on his computer to a research paper on “levitating particles,” a possible alternative to sulphate. For months, he wasn’t able to bring himself to submit it for publication. “I’m worried about opening up Pandora’s box,” he explains. “Even though I am basically doing it.”