When it comes to climate change, says Gernot Wagner, “uncertainty” is a powerful word. It just doesn’t mean what people think it does.
The economist, author, and co-director of Harvard’s Solar Geoengineering Research Program says too many policymakers have framed climate change as a matter of uncertainty, rather than risk.
“One of the primary responses by those not wanting to do sensible climate policy is ‘Oh, we don’t know enough!’” he told the Knight Science Journalism fellows on Sept. 26, adding: “With uncertainty, people tend to say, ‘Oh, let’s wait and see. We need to do more research.’”
But it’s precisely this uncertainty, he said, that should shock people into action. That is the main contention of the 2015 book “Climate Shock,” which he wrote with Martin Weitzman, an environmental economics professor at Harvard.
“It’s the stuff that we don’t know that’s much, much worse than the stuff we do know.”
By current estimates, global temperatures will rise 1.5 to 4.5 degrees Celsius within this century, largely because of our continued production of carbon. Here, Wagner is quick to point out a couple of things: that climate change is inescapable, and that there is still a chance it may be worse than we expect.
“This is scary enough, of course. The averages are bad enough. But there is a non-zero probability” of a much greater rise, he warned: 6 degrees Celsius or more. “The probability of that happening should really prompt us into action.”
But as with an overflowing bathtub, the solution isn’t as straightforward as simply minimizing our carbon emissions. You can’t just turn off the tap, Wagner said; you need to unclog the drain too.
Completely shutting down carbon emissions would pull down global temperatures in the long term but would also eliminate sulfur dioxide — which, in turn, would cause a global temperature spike “within weeks.”
“Sulfur dioxide is basically tiny reflective particles,” he explained. “The fact that it’s tiny is bad because kids breathe it and die from asthma as a result, but the fact that they’re reflective means that they’re cooling what’s underneath — the albedo effect.”
And that’s where his Solar Geoengineering Research Program comes in. The goal of the $8 million project is to study the effects of interventions “to make the planet more reflective,” from painting roofs white to ambitious proposals like seeding the stratosphere with sulfur dioxide using specially modified airplanes flying round the clock. (The initiative is funded by the William and Flora Hewlett Foundation, the Open Philanthropy Project, the Pritzker Innovation Fund, the Alfred P. Sloan Foundation, the VoLo Foundation, and the Weatherhead Center for International Affairs.)
“Volcanoes have been doing it forever,” Wagner said, pointing out that the explosion of Mount Pinatubo in the Philippines in 1991 temporarily caused global temperatures to drop by half a degree, the total average global warming up to that point.
Wagner admits that he has his job cut out for him: It’s his responsibility to look at the social impact of geoengineering.
“My part in this is the social science,” he said. “What is the interaction of even just talking about mitigation? In so many ways, it’s the bigger impact … the impact of even just talking about researching the topic on people’s desire to cut emissions in the first place.”
KSJ Fellow Mićo Tatalović said he was struck by “the idea that so few of us consider the consequences of the upper end of global warming … and it looks like global warming might well be worse than our early models have predicted.” Geoengineering, he added, “will have planetary consequences — for better or worse.”