Atmospheric Manipulation

Scientists envision a fleet of 1,500 unmanned, wind-powered ships to shoot saltwater into ocean clouds. They predict increasing reflectivity by 10 percent would stabilize the Earth’s temperature for 50 years. Photo: John MacNeill

It might take a bit of imagination to save the planet

By Amanda Pterka
Fall 2008

Twenty years ago John Latham proposed a crazy idea: spraying saltwater into the air to curb the effects of global warming.

That plan is now gaining ground in the environmental science community as emissions, and subsequently global temperatures, continue to reach unprecedented levels.

Broadly labeled “geoengineering,” theories like Latham’s aim to cool the Earth by blocking some of the sun’s rays.

He and his partner, Stephen Salter of the University of Edinburgh, U.K., are running computer-simulated tests on a plan to use a worldwide fleet of about 1,500 autonomous, wind-powered ships to inject saltwater into low-lying ocean clouds. The boats would use 40-foot-tall columns to continuously shoot water into the air. The hope is that turbulence will carry about half of those water particles into the clouds. The goal is to increase the clouds’ concentration of water droplets and reflect more sunlight away from the Earth. Latham predicts that by increasing reflectivity by only 10 percent, the boats could stabilize the Earth’s temperature for 50 years.

Latham said these broad planetary schemes are overdue.

“I think governments have been really quite complacent about the global warming issue, and we’re rapidly approaching a situation where some kind of action of this kind is going to be needed,” said Latham, a scientist for the University Corporation for Atmospheric Research, a branch of the National Center for Atmospheric Research.

But not all scientists have jumped on the geoengineering bandwagon. Many, such as senior scientist Jay Gulledge of the Pew Center on Global Climate Change, oppose the ideas they view as grandiose, quick-fix solutions to a complex problem.

“You’re directly manipulating the surface energy balance of the Earth and doing it on a very vast time scale. This energy balance is what determines winds, rains, all our basic climate processes,” Gulledge said.

“I think people have this tendency to think of climate as a thing that cannot be affected quickly. But if you quickly alter the incoming solar radiation, climate will change abruptly, and that’s a scary thing with unintended consequences.”

Pumping sulfur into the air to create a haze to dim the sunlight that reaches the Earth would change the climate abruptly. Climate scientist Ken Caldeira is running computer-simulated tests on the idea, inspired by the 1991 Mount Pinatubo eruption that covered the planet in a sulfur dioxide shade. That eruption made global temperatures fall within a year. While the idea may seem far-fetched, the tests and Pinatubo suggest it would cool the planet.

But scientists say it is difficult to predict how these ideas work on a global scale. Geoengineering opponent and climatologist Stephen Schneider believes the consequences could be dire. He mentioned a host of things that could go wrong for the environment and for society.

“You don’t know if you’re going to over or under compensate. You perform the experiment, but you’re performing the experiment in a laboratory called Earth,” Schneider said.

Other geoengineering ideas include orbiting trillions of mirrors to deflect sunlight, and pumping iron into the oceans to increase plankton, which absorb carbon dioxide. The latter idea differs in its focus on CO2 rather than sunlight.

Michigan State University geoengineering researcher Millind Khire said he would rather see more research on removing carbon from the atmosphere, through sequestration and smaller-scale operations.

“The experiments [scientists are] doing right now may have positive results, but at the scale of the planet, it’s a totally different experiment,” he said. “All experiments have a scale effect. Local and regional are not the same as the planet scale.”

Rutgers University meteorologist Alan Robock has written extensively about the possible consequences of manipulating the planet. In a paper titled “20 Reasons Why Geoengineering May Be a Bad Idea,” he lists environmental concerns such as effects on regional climate, ocean acidification (due to the iron), ozone depletion (which would accelerate warming) and unknown effects on plants and photosynthesis.

“I don’t want to bet the future of my planet. I’d much rather get rid of the problem in the first place,” Robock said. “Additional pollution to the atmosphere to block out the sun is fraught with danger.”

Gulledge contends that if something goes wrong, these planetary solutions may be hard to reverse, especially the sulfur idea. “Switching off” a large-scale project may not be as simple as stopping the sprayers. Warming could happen quickly — not like the gradual warming Earth is experiencing.

Most scientists agree that more research is needed before anyone seriously considers drastic action. But despite everything that’s still unknown about the ploys, Robock said businesses may back the ideas. “American enterprises come out in favor of [geoengineering]. It gives them a free pass to continue business as usual,” Robock said. “Someone else pays to clean up their mess, like buying indulgences.” These ideas would cost considerably less than it would to clean up damage if we don’t do anything, Lantham said. Still, testing the ideas is expensive —

Lantham’s saltwater idea would cost about a billion dollars a year. And while Britain recently commissioned a geoengineering study, governments largely have not invested in the research. That’s good news to Robock. “The idea that you can actually solve the problem like this takes away from the political will to do mitigation,” he said.

Supporters and critics of such schemes’ are largely motivated by the opportunity for financial gain, Schneider said. They are attractive to the oil and coal industries, developing countries and SUV producers. But Chevy Volt dealers may be less enthused.

“Some people will think it’s ungodly,” he said “Others will think it’s really cool and clever. What’s going to account for people’s views? But in the end I think they’re going to ask, ‘what it’s going to do to my industry and my job’ and ask selfish questions rather than go with what’s good for the Earth.”

Amanda Peterka is a senior journalism major at MSU. This is her fifth appearance in EJ. Contact her at peterkaa@msu.edu.