Kevin Bullis

A View from Kevin Bullis

Warming Planet? Engineer Plants to Reflect Light Back into Space

Announcing this year’s so-crazy-it-might-work award from the ARPA-E Summit.

  • March 1, 2013

Every year at the annual Advanced Research Projects Agency for Energy Summit (which took place this week) you can count on there being at least one left-field idea that just might work—or might go horribly wrong.

Here’s my nominee for this year’s so-crazy-it-might-work award.  On the first day of the conference, Robert Conrado, a senior fellow at ARPA-E, took the stage to describe his idea for addressing a big problem with agriculture and biofuels: plants use a huge amount of water just to stay cool. Only 1 percent of water they take up goes to making the carbohydrates and other materials that make up the plant. The rest, Conrado says, is for temperature regulation. Worldwide, 90 percent of water use goes to watering plants, which of course limits food production. It also limits where biofuel crops can be grown.

The solution Conrado proposed has to do with the fact that plants can use only a narrow part of the solar spectrum to conduct photosynthesis. They can’t use infrared and ultraviolet light, which just go to heating the plant up, forcing it to suck up water to cool off.

Conrado put up a slide showing a peacock, a butterfly, and a strangely colored berry. These all grow microscopic structures that are tuned to interact with specific colors of light, producing brilliant coloration.

He asked, why not engineer plants to grow similar structures designed to reflect the light they can’t use? That would reduce the cooling needs of the plants. Reflecting infrared light would reduce water consumption by one-third and would make it possible to grow plants for biofuels in currently water-constrained areas. Some of the light would reflect back into space, he suggested, helping to offset global warming. (Much of the reflected light would be absorbed by water vapor in the atmosphere, however.)

What could go wrong?

Seriously—I’m curious about what people think of this idea. What should researchers watch out for if they try to do this? 

Tech Obsessive?
Become an Insider to get the story behind the story — and before anyone else.
Subscribe today

Uh oh–you've read all five of your free articles for this month.

Insider Premium

$179.95/yr US PRICE

More from Sustainable Energy

Can we sustainably provide food, water, and energy to a growing population during a climate crisis?

Want more award-winning journalism? Subscribe to Insider Plus.

  • Insider Plus {! insider.prices.plus !}*

    {! insider.display.menuOptionsLabel !}

    Everything included in Insider Basic, plus ad-free web experience, select discounts to partner offerings and MIT Technology Review events

    See details+

    What's Included

    Bimonthly home delivery and unlimited 24/7 access to MIT Technology Review’s website.

    The Download. Our daily newsletter of what's important in technology and innovation.

    Access to the Magazine archive. Over 24,000 articles going back to 1899 at your fingertips.

    Special Discounts to select partner offerings

    Discount to MIT Technology Review events

    Ad-free web experience

You've read of free articles this month.