January 28th, 2016


Climate Scientist, Carnegie Institution for Science, Department of Global Ecology at Stanford University

Briefings Editor, The Economist

Author, The Ministry for the Future


In an emergency, we’re told to “break the glass” and reach for the fire extinguisher.  Some would argue we’re in the midst of a climate emergency – so what’s the solution?  Can we spray a firehose into the sky to cool down our atmosphere?  It may sound like science fiction, but there are climatologists who believe we can – and should – do something very much like it.

It’s called geoengineering, and as climate scientist Ken Caldeira explains, there are basically two approaches to cooling the earth.  One is to remove the carbon dioxide we’re adding to the atmosphere. The other is “basically, to emulate what big volcanoes do,” he explains, “put material in the stratosphere to reflect sunlight.”

As early as 1965, scientist Roger Revelle warned President Johnson of the effects of greenhouse gases on the climate, and suggested putting “lots of little reflective bubbles on the surface of the ocean.” More recent climate-fixing experiments include spraying reflective material into clouds and dumping iron into the ocean to increase photosynthesis.

Critics have predicted that tinkering with the stratosphere in this way could lead to a man-made ice age; just such a scenario was the premise of the 2013 sci-fi film Snowpiercer. But science fiction author Kim Stanley Robinson says those fears are unfounded; as we’ve seen from the volcano example, such cooling would be only temporary, “so it's a little bit safer than other things that might be suggested.”

Still, Robinson continues, there could be a third option for remaking the planet: remaking our societies. “If we plant a lot of forests, if we give all the women on the planet their full legal rights, we've changed the climate of the earth in a radical way - so that's geoengineering too.”

At the U.N. Summit on Climate Change in Paris, the governments of the world set an ambitious goal of keeping global warming to under two degrees Celsius. “But in order to meet those targets, the governments basically need to remove large amounts of carbon dioxide from the atmosphere later in the century,” says Caldeira.  “So essentially, geoengineering in the way of removing carbon dioxide from the atmosphere is the implicit policy of every major government in this world right now.”

Oliver Morton of The Economist is concerned about a too-hasty “break the glass” approach.  “At a time when the earth is already going through severe climate changes and geopolitical panic is exactly the wrong time to launch a large planet-changing sort of effort,” he warns. “It seems to me that it's much, much wiser to talk about introducing small amounts of geo-engineering at a time when the world is not completely freaked out than large amounts of the time when it is.”

“Unfortunately, the most environmentally responsible way is also the most politically difficult,” counters Caldeira. “If there's a leader of a country whose people are starving, and they think by injecting some particles in the stratosphere they can feed their people and alleviate suffering, the political pressure to do that is going to be intense.”

What about a fourth option – if we can’t take the heat, should we get out of the kitchen? Space travel is already a reality.  Can we load up our rocketships and find a cooler world to inhabit?

That solution is still a long way off, believes Robinson. “This is the only planet we can live on and stay healthy, and I think that will be true for tens of thousands of years,” he says. “So there is no Planet B.

“But studying these other places, sending robots with cameras and sending people as scientific stations the way we sent people to Antarctica a century ago - it’s all fantastically interesting and exciting and useful and beautiful.”

We should appreciate that we already live on “an extraordinary planet,” agrees Morton.

“And we understand that planet far better than we ever have before,” he continues. “And simply trying to partake of some of that understanding with the spirit of reverence and a spirit of awe…but also with the spirit of fascination and wonder at the mechanisms involved - I think that's both politically useful, and I think it's life enhancing.”


Related Links:

Kim Stanley Robinson: Green Earth (The Science in the Capital)

Oliver Morton: The Planet Remade: How Geoengineering Could Change the World

National Academy of Sciences Report: Climate Intervention: Reflecting Sunlight to Cool Earth

Bipartison Policy Center Task Force on Geoengineering

Policy Report: Start research on climate engineering


Written by: Anny Celsi
Photography by: Ed Ritger