How Brighter Clouds Fight Climate Change (Without Dr. Strangelove)

In 1990, a British cloud physicist named John Latham wrote a letter, [PDF] to the journal Nature, in which he suggested that injecting tiny droplets of water into marine clouds to increase their reflectivity might be a way "to inhibit or neutralize global warming."

And then? "Nothing happened for 10 years except for a couple of angry letters saying it was a horrible thing to play God and why didn’t I go knock on the door of the president and tell him to stop burning fossil fuels," Latham recalls.

But as greenhouse gas emissions kept growing, Latham’s odd idea gained traction. It spawned a succession of peer-reviewed scientific papers, sparked debate in the scientific community and eventually led to the organization of a loosely-knit group of international scientists who now want to see if brightening marine clouds might actually be a feasible way to slow down or stop global warming.

"We’d like to move towards a limited-area field experiment," Latham says.

I met Latham — a leading thinker in the emerging field of geoengineering — last week during a fellowship at the National Center for Atmospheric Research (NCAR). He is 73 years old, semi-retired and unpaid, but passionate about putting his scheme to a test. Latham is collaborating with about two dozen scientists, including "a couple of other geriatrics" (his words, not mine) who play key roles: Stephen Salter is a British engineer who came up with the idea of using unmanned, satellite-controlled, wind-powered ships (below) to travel the oceans and disseminate the seawater, and Armand Neukermans is an inventor and entrepreneur (he helped develop inkjet printer technology at Hewlett Packard) who is working on developing a sprayer able to deliver very fine seawater droplets to the clouds. Interestingly, Neukermans’ research has been supported by a small grant ($300,000) from a fund established by Bill Gates to support innovative climate and energy research.

Latham recognizes that there are dangers in trying to manage, on a global scale, a system as complex as the earth’s climate, the very definition of geoengineering.

"Geoengineering is a horrible word," he said. "It makes people think of Dr. Strangelove.

"I don’t know anyone working in geoengineering who wants deployment to happen," he added.

The trouble is, he said, as greenhouse gas emissions rise — they reached a record high in 2010, according to the International Energy Agency – so does the risk of catastrophic climate change.

“There are no signs that we are behaving responsibly with respect to future generations,” he said. It would be irresponsible, he argues, not to look into alternatives since mitigation has failed, so far, to do the job.

Next page: Understanding cloud behavior to save the climate