As Brad Plumer points out it’s somewhat unfortunate that the term “geo-engineering” has emerged as a kind of catchall for “things that could mitigate climate change that don’t involve reducing carbon emissions” even though some of this stuff is well into mad scientist territory while some of it is totally sensible. He offers a taste of the sensible:
But geo-engineering doesn’t always have to be so drastic. Earlier this week, a new study from the Institute of Mechanical Engineers in Britain laid out some smaller-scale measures to cool the Earth, and all looked a lot less problematic. We could, for instance, paint all our roofs white, reflecting more of the sun’s heat and cooling the Earth. That’s a form of geo-engineering, and one that’s less likely to have unforeseen side effects than pumping chemicals into the sky. (Though granted, white roofs don’t actually take carbon out of the air, so they do nothing to prevent, say, ongoing ocean acidification.)
The report also touts new artificial trees under development that could potentially remove carbon-dioxide from the air more efficiently than regular trees do. Planting 100,000 such trees on a 1,500-acre area, for instance, might in theory be able to absorb the carbon emissions from Britain’s entire non-power sector. Likewise, engineers could put tubes filled with algae on the side of buildings—the algae would absorb carbon-dioxide from the air and could then be collected, turned into charcoal, and buried underground, trapping the carbon for all eternity.
At some margin, these kind of measures are going to be cheaper and easier than further reductions in carbon emissions. At the same time, it really is worth emphasizing that there’s no reason to believe that that margin is the margin we’re actually at right now. It’s easy to talk about tubes filled with algae as an alternative to a hard cap on carbon emissions if what you want to do is ensure that American Climate and Energy Security bill dies in the U.S. Senate. More difficult is to actually pass the bill that raises taxes and spends the funds on constructing these algae tubes. And honestly it’s just common sense that as long as we’re installing new stuff on buildings everywhere it would be easier to install programmable thermostats and better insulation—proven technology that exists and is working happily on many places—and directly reduce emissions.
That said, trying to get people to paint roofs white seems like a total no-brainer and given how solid the science behind this is I don’t really understand why there isn’t more momentum behind it. Manufacturers of white paint need to hire some better lobbysist or something.