The Internet has been abuzz about a new technique for fighting climate change by sucking carbon dioxide out of the air. As reported in The Atlantic:

A team of scientists from Harvard University and the company Carbon Engineering announced on Thursday that they have found a method to cheaply and directly pull carbon-dioxide pollution out of the atmosphere . . . . As recently as 2011, a panel of experts estimated that it would cost at least $600 to remove a metric ton of carbon dioxide from the atmosphere. The new paper says it can remove the same ton for as little as $94, and for no more than $232.

This process is one example of a broader set of approaches known as “geoengineering,” which seek to cancel or offset the effects of human-caused climate change. If this new approach works as advertised, it represents a positive step. But while the prices listed in the article are certainly *cheaper* than what has been previously estimated for direct air capture, it would be a mistake to call them cheap. To offset current levels of CO2 emissions at these prices would cost between $3 trillion and $7.5 trillion a year, or around five to ten percent of global GDP.

Even at the low end of the cost range, $94 a ton is still more than double the Obama administration’s estimate of the amount of damage done by a ton of carbon dioxide emissions (and is nearly 20 times the new Trump administration’s estimate). Going by the Obama numbers, using this technology on a large scale simply would not be worth the cost. And even if you thought the Obama administration had vastly underestimated the dangers of climate change, you would still only want to use a technology this costly once you had taken advantage of any cheaper ways to reduce emissions (of which thankfully there are many). This method is not even the cheapest technique for geoengineering (although some other possible methods tend to be more controversial).

To really be a breakthrough, technologies to counteract the effects of climate change need to be a lot cheaper, and the possible side effects need to be studied. The good news is there is every reason to think technologies like this can get a lot cheaper if we put in the effort.

One way to do this would be to charge a per ton fee for CO2 emissions. Right now the cost to a business of emitting an extra ton of CO2 into the air is close to zero. As such, they have little incentive to figure out how to make carbon capture cheaper. If a company had to pay for each ton of CO2 it emitted, it would have a strong incentive to develop cheap carbon capture technologies.

There is also a strong case for increased government research funding in this area. At a hearing before the House Science Committee earlier this year, witnesses testified that only a few million dollars a year was being spent on geoengineering research globally. Frankly, that is a pathetically small sum when you consider the potential import of the issue.

Some on the environmental left oppose research into geoengineering on the grounds it would undermine efforts to reduce greenhouse gas emissions. If people knew that there was a cheap, safe way to counter-act the effects of climate change, the argument goes, they would give up on efforts to reduce emissions in the first place. Concern that even studying the issue would create this “moral hazard” has helped keep geoengineering funding at its current frustratingly low levels. Yet as the reaction to The Atlantic story shows, any moral hazard created by the prospect of geoengineering is already largely baked in. No additional research is necessary to know that geoengineering is a potential response to climate change. Additional research might show that it would not work, or that it would have unacceptable side effects. But no additional research is necessary for people to argue that geoengineering means we do not have to reduce emissions, if that is what they want to do.

To quote Emil Faber of “Animal House” fame, “knowledge is good.” Learning more about how geoengineering techniques would work – and how to make them really cheap – could pay planetary sized dividends.

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