12:16pm

Wed July 31, 2013
Science

Geoengineering: The Technological Fix to Climate Change?

You may have missed it, but last week national headlines read, “the CIA wants to control the weather.”  Those headlines came on the heels of the media learning the CIA was funding a report on geoengineering. It’s an idea that’s akin to a man-made thermostat for the globe.  Aspen Public Radio’s Science Reporter explains what geoengineering is, why you need to know about it, and why the CIA is involved.

Over the next year, a team of experts will assemble an exhaustive report on what we know, and don’t know, about geoengineering. The panel, assembled by the National Academy of Sciences, is being funded by a slew of federal agencies including the National Science Foundation, the National Oceanic and Atmospheric Administration, and the CIA. Meteorologist David Titley from Penn State is one of those scientists. He says geoengineering is,

“The intentional modification of climate by man to un-do some of the changes to the climate that we have already inadvertently created.”

If that sounds like a big task—completely reversing the current trajectory of our climate—well, it is. Geoengineering, if it were to be done, would be the largest-scale engineering project in human history. Ed Dunlea is overseeing the report. He says the panel will focus on two main geoengineering strategies.

“Those that are designed to remove carbon dioxide from the atmosphere, and then also those that are designed to mitigate the amount of sunlight reaching the surface.”

Ideas to remove carbon dioxide often involve the oceans. The predominant idea is to dump vast quantities of iron into the water to promote the growth of algae. Algae would suck CO2 out of the sky, and store it at the bottom of the ocean.

The other geoengineering strategy calls for blocking out the sun’s rays. Joyce Penner is an atmospheric physicist on the committee.

“It’s very similar to a large volcanic eruption.”

A volcano sends tons and tons of tiny particles, or aerosols, into the upper atmosphere. There they block sunlight, resulting in less warming at the earth’s surface, says Penner.

“The last huge volcano was Pinatubo, which went off  in 1991. We had instruments that were able to measure a lot of the properties of the aerosols that formed and also measure the global temperature drop after Mt. Pinatubo.”

Geoengineering would mirror what a volcano does, only it would be like the eruption would happen over and over. On the ground, the geoengineer’s job would be to continuously pump particles into the sky.

“We kind of understand how to do that. We know how to get aerosols up to 100-thousand feet, give or take. And we understand that while it’s expensive, it’s in the billions of dollars, it could still be afforded by quite a number of countries,” says Titley.

Yes, you heard that right: a few billion dollars is all it would take to launch an earth-scale thermostat. And with rising global temperatures, there is a growing urgency to understand how geoengineering would work, and what consequences it might bring. Again, Ed Dunlea.

“There’s a lot of discussions that need to happen around this topic, and our goal is to inform those discussions with sound scientific understanding.”

One of those discussions, says Alan Robock, a meteorologist at Rutgers, is that geoengineering would open a Pandora’s Box.

“How could you decide what the planetary temperature would be, whose hand would be on the thermostat? How could you get a global agreement on what the temperature should be? ”

He says even if there could be agreement about where to set the global thermostat dial, many side effects, known and unknown, would present themselves.

“If you did that, there would be regional changes in precipitation, also. All the summer monsoons around the world would be weaker. You would destroy the ozone, by putting particles up into the stratosphere. You would do nothing to stop ocean acidification.”

And that’s just one. You can add ozone hole depletion and uncertain effects on crops to the list.

Despite these concerns, the National Academy of Sciences and the CIA, see exploration of geoengineering as a worthy exercise. It may be a tool that governments use in a warmer future. The CIA funding the study isn’t that surprising. They’ve funded climate change research in the past as an issue of national security. However, their support, when contrasted with the rhetoric of congress, underscores the wide range of viewpoints on the issue of climate change.