Air Date: Week of February 16, 2007

British billionaire Richard Branson is offering a 25 million dollar prize to the scientist with the best plan to remove excess carbon dioxide from the atmosphere. Living on Earth’s Emily Taylor reports on three scientists who are already working on projects to reduce CO2, and about the Branson challenge.

Transcript

CURWOOD: Trees and other plants take carbon dioxide out of the air every day, and thereby slow down the rate of global warming. So what if we could devise a technology to pull carbon out of the atmosphere fast enough to stop climate change in its tracks? Well, if you come up with the answer, billionaire businessman Richard Branson is prepared to hand you up to $25 million in prize money.

All you have to do is develop a proven and reliable technique to get a billion tons of carbon out of the atmosphere in the course of a year. As of today, of course, that’s considered impossible. But then again for thousands of years we thought people couldn’t fly and certainly couldn’t go to the moon. So Living on Earth’s Emily Taylor asked some leading scientists what approaches might win this so-called Branson challenge.

TAYLOR: The official title is the Virgin Earth Challenge, it’s named after the many businesses in Richard Branson’s empire including Virgin Records and Virgin Atlantic Airways. The challenge is aimed at finding a way to capture the excess carbon dioxide that humans are putting into the atmosphere. Natural processes already capture billions of tons of atmospheric CO2. But things like gasoline powered cars, coal fired power plants, and Branson’s jets are producing far more CO2 than the natural carbon cycle can absorb; three and a half billion tons more every year. Branson is hoping his 25 million dollar prize will motivate scientists to find a way to capture about a third of that excess CO2. Of course some scientists have been thinking about this challenge for years. One of them is J. Craig Venter. He’s the geneticist who gained notoriety when he raced the federal government to map the human genome.

VENTE R: We’re trying to meet the challenge of removing CO2 by designing a new set of microbial cells using our synthetic genomic capabilities to do what we find in deep ocean organisms capture CO2 and convert that CO2 by fixing the carbon into sugars, proteins, ah, various kinds of lipids or biopolymers.

TAYLOR: Venter says that the carbon stored in his synthetic organisms could then be extracted and used in carbon heavy manufacturing processes. That would kill two birds with one stone since most industrial carbon now comes from petroleum.

VENTER: Clothing, carpets, pharmaceuticals, ah, plastics all come from the petrochemical industry so, ah, if all the carbon that goes into plastics comes from CO2 versus oil we don’t have to take the carbon out of the ground.

TAYLOR: Other scientists would also use the oceans to help reduce carbon levels. John Latham is at the National Center for Atmospheric Research. He proposes increasing the number of droplets in the low-lying clouds that often form over the ocean. Latham says this would make the clouds reflect more sunlight, which would help to cool the planet.

LATHAM: If we can make those clouds reflect about an extra three percent or something like that then there will be a cooling because less sunlight is getting to earth. And because the solubility of carbon dioxide in water increases as the water gets cooler the more CO2 that’s in the air will get trapped in the oceans.

TAYLOR: Here’s how Latham’s plan would work.

LATHAM: We propose to spray from special, unmanned satellite guided vessels, sea water droplets, very small ones about one ten thousandth of a centimeter in size. Um, and they act as centers for production of additional droplets. So we’ll in that way increase the reflectivity of these clouds.

TAYLOR: Another big idea would mimic one of nature’s most effective means of regulating carbon dioxide. Klaus Lackner teaches at the school of engineering and applied sciences at Columbia University.

LACKNER: The way to get carbon dioxide out of the atmosphere is akin to how a tree does it. It puts surfaces up, the leaves, over which the CO2 flows and as the air flows the CO2 is being absorbed. Once you have absorbed that on a surface which is let’s say wetted with a liquid you can collect that liquid and then remove the CO2 from that liquid.

TAYLOR: Lackner says the CO2 could then either be disposed of under ground or used in manufacturing processes like making cement. Lackner envisions putting up thousands of these collectors across the globe to suck up emissions from cars and industry.

LACKNER: I sort of sketched out some time ago a tower which is the size of a water tower for a small town. And such an object by itself could take care of about 15,000 cars, again like the size of that small town. And if you had 250,000 such towers world wide, which is not a terribly large number, you would take out as much carbon dioxide as the world is putting into the atmosphere right now.

TAYLOR: So, new microbes, sea water spraying vessels, or giant fake plastic trees. Whether any of these ideas or any others will do the trick remains to be seen. Richard Branson himself isn’t sure if his 25 million dollar prize will ever be awarded and he makes it clear that governments and private industry will have to invest much larger sums still, to find feasible solutions to the problem of excess carbon dioxide in the atmosphere.

For Living on Earth I’m Emily Taylor.

 

Links

The Virgin Earth Challenge

John Latham's webpage

J. Craig Venter's webpage

Klaus Lackner's webpage