Skip to main content

The Globe and Mail

The promise and the peril of an engineered climate

Prof. Edward Parson fears the prospect of humankind engineering its way out of the consequences of climate change will lead to complacency about doing something about its causes.

Tim Fraser/tim fraser The Globe and Mail

Yesterday's climate-change worry: addiction to oil. Tomorrow's climate-change worry: addiction to geo-engineering - the quickest, cheapest, most effective way of blocking global warming that is increasingly being embraced by fashionable proponents of fixing Earth.

To the University of Michigan's Edward Parson, one of the world's leading scholars on the politics of climate change, geo-engineering is raising the spectre of what he calls "nutty, delusional cheerleading," a facile rush to trumpet a massive scientific rescue of the Earth from the doomsday scenario of rising temperatures.

The bestseller SuperFreakonomics by University of Chicago economist Steven Levitt and New York Times journalist Stephen Dubner - given three and a half stars out of five by Business Week - devotes a whole chapter to the notion of pasting the planet with sun block by pumping sulphur dioxide into the stratosphere.

Story continues below advertisement

It borrows the patented idea from former Microsoft boffin Nathan Myhrvold, who wants to emulate the impact of the 1991 volcanic eruption of Mount Pinatubo, which cooled the Earth's temperature by half a degree Celsius in a single year with an explosive spewing of sulphates into the stratosphere that blocked the sun's radiation.

Mr. Myhrvold would do the same by pumping sulphur dioxide from Earth's surface into the heavens through a 25-kilometre-long tube.

A few weeks ago, Britain's Royal Society teamed up with the U.S. Environmental Defence Fund and the Third World Academy of Sciences to investigate potential models of international governance for geo-engineering - a project of which Prof. Parson strongly approves, along with indications the U.S. government is looking at funding research.

He said research has to be done on how, when and by whom geo-engineering, or solar radiation management (SRM), can be deployed because it is expected to be so cheap, fast and effective that "it puts it within the capability in principle of so many actors." Thus, he said, the world's nations must also develop a governance capacity "so that we can make decisions about whether we need it, and deploy it without getting into fights."

It likely would involve some concept of putting sulphur dioxide into the stratosphere.

"It's the only thing we could do that has the possibility of seriously stopping bad things happening after we know they are," said Prof. Parson, a Canadian, who spoke last week at the University of Toronto on the ethics of dealing with climate change. He has been an adviser to the United Nations, the U.S. Congress, the Clinton White House and the Privy Council Office of the Canadian government.

"So suppose we find ourselves in 30 years in a situation where climate change is much faster and much worse than we'd imagined - we wish we'd done better back in 2010 and 2000 and 1990, but it's too late - this is a Band-Aid. It's a corrective."

Story continues below advertisement

The addiction worry, said Prof. Parson, is that SRM will be deployed and people will say, "'We don't need to worry about cutting C02 emissions because we've got this'. Now, if it were perfect, that would not be a problem. But it's really not. And so we really can't rely exclusively or predominantly on this. That's the imperfect."

Scientists believe that SRM could counterbalance a temperature increase of three to four degrees caused by greenhouse gas emissions. But if greenhouse gas emissions aren't drastically cut, once SRM was turned off, temperatures would bounce up by three or four degrees within a year with unknown consequences, said Prof. Parson.

Scientists also believe that by putting sulphates into the stratosphere and reducing sunlight, which is absorbed at the Earth's surface, SRM would affect the water cycle and therefore precipitation. And because what goes up must come down, the sulphates would result in an increase in acid rain. Prof. Parson said. There also could be significantly different regional impacts, he said. "So a lot of people worry about messing with the Asian monsoon, for example." Prof. Parson said.

"And then the last and perhaps gravest respect with which it's imperfect is that it offsets the radiative or climatic effects of elevated greenhouse gases but it does nothing to address the direct environment impacts of elevated carbon dioxide by itself."

Given all the risks, the SRM should still be developed - although not necessarily ever deployed, he said.

"We need to have it in reserve as a contingency plan against two possibilities: that we continue to screw up so badly and fail to reduce emissions, and that the climate impact uncertainties [of failing to reduce emissions]come in really bad."

Story continues below advertisement

Report an error Editorial code of conduct Licensing Options
As of December 20, 2017, we have temporarily removed commenting from our articles. We hope to have this resolved by the end of January 2018. Thank you for your patience. If you are looking to give feedback on our new site, please send it along to If you want to write a letter to the editor, please forward to