The Outlandish, Scary Schemes Being Studied to Cool the Planet

(Bloomberg) -- Plan B is coming out of the shadows in the global-warming debate. The question on the table: With hope dimming that humankind can effectively curb carbon emissions, is it time to strong-arm nature to turn the thermostat down?

To scientists who study geoengineering, this is within the realm of possibility. The idea is to manipulate the climate, by planting millions of trees to clear the air or -- at the other extreme -- creating a mirror of chemicals in the heavens to reflect the sun’s heat away from Earth. Some of the schemes are outlandish, if not downright scary. A small though increasingly vocal band of experts in the field contends the options must at least be explored.

Scientists including David Keith at Harvard University and Antonio Busalacchi of the University Corporation for Atmospheric Research are advocating that more resources be devoted to the discipline.

“Suddenly all sorts of people who five years ago would have said, ‘Shut up, this is too controversial, I don’t want to talk about it,’ now agree something should happen,” said Keith, a professor of applied physics and public policy and a member of a team planning a field experiment this year to test whether shooting sulfate aerosols into the stratosphere might limit solar radiation.

Ferocious Debate

As it is, he said, “there is very little research going on.” There is ferocious debate about the efficacy -- and ethics -- of climate intervention, even among academics who specialize in it. What’s bringing it to the fore is a recognition the international community probably won’t meet its markers for cutting back on the man-made gases that, according to the consensus, contribute to rising temperatures.

“We are past a point of no return in the quest to avoid dangerous warming,” said Clive Hamilton, the author of 2013’s “Earthmasters: The Dawn of the Age of Climate Engineering” and a professor at Charles Sturt University in Canberra, Australia. “Have we reached the geoengineering tipping point? I don’t see it yet, but it will come.”

Some geoengineering ideas don’t have big frills: painting roofs white to reflect infra-red rays, for instance. The private sector and governments have pursued small-scale weather massaging, such as when China used rockets to divert rainfall from the 2008 Olympics opening ceremony.

Fertilize Oceans

Then there are the massive, planet-wide endeavors being investigated on paper and in the lab: spraying marine clouds with saltwater to make them paler so they’ll bounce more sunlight back into space or injecting microbubbles into the Pacific and Atlantic oceans for the same effect; thinning out cirrus clouds with biological agents to allow heat to escape into the atmosphere; using powdered iron sulphate to fertilize oceans and stimulate phytoplankton growth that will draw carbon dioxide from the skies.

“It is the extremely risky ones that are getting all the attention,” Hamilton said. They’re “so full of dangers it is surprising people take it seriously.”

In theory, geoengineers could even mimic the climatological effects -- without the deadly consequences -- of a massive volcanic eruption like the one at Mount Pinatubo in the Philippines in 1991 that spurred a 0.5 degree Fahrenheit drop in global temperatures.

Tim Kruger, manager of the Geoengineering Programme at the University of Oxford, said he knows how complicated, and often frightening, his field can seem. But sensible alternatives must be considered because governments that signed the Paris Agreement “have seemingly not internalized what it would take to achieve it.”

Paris Accord

The Paris accord commits to holding the increase in the average global temperature “well below” 2 degrees Celsius (3.6 Fahrenheit) above pre-industrial levels, and to aim for 1.5 degrees.

The United Nation’s Intergovernmental Panel on Climate Change is at work on a report that is expected to throw cold water on hope for the 1.5 degree goal without some manner of geoengineering. Even 2 degrees is widely viewed as unobtainable, particularly with President Donald Trump having pledged the U.S. will pull out of the climate pact.

According to Neil Craik of the University of Waterloo in Ontario, Canada, “the only way to get to 2 degrees is by removing carbon dioxide from the atmosphere.” Can that really be done? The European Academies Science Advisory Council recently cast doubt on the prospect. It’s something the world needs to fully investigate, Craik said, because it it isn’t clear “we can get removal to work at the scales necessary.”

‘Throwing in the Towel’

For many, climate intervention means “throwing in the towel,” UCAR’s Busalacchi said. “There’s been a healthy dose of resistance in the research community. If attention is diverted to geoengineering, that would mean taking the focus off mitigation and reduction in greenhouse gases.”

There are plenty of reasons to be wary. Beyond the unknown effects on the ecosystem and humankind, investments in geoengineering could siphon money from developing renewable energy and less-polluting vehicles, said Silvia Ribeiro, Latin American director for ETC Group, a nonprofit that analyzes technology’s impact on society.

Those efforts have carbon-reducing track records while geoengineering is “magical thinking,” she said. Maybe, but according to Busalacchi, with the race on to prevent climate-change disaster, now’s the time to “consider and have all tools on the table.”

--With assistance from Eric Roston

To contact the reporter on this story: Brian K. Sullivan in Boston at bsullivan10@bloomberg.net.

To contact the editors responsible for this story: Lynn Doan at ldoan6@bloomberg.net, Anne Reifenberg, Melinda Grenier

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