No, Climate Change CAN’T Be Stopped by Turning Air Into Gasoline

My award for dumbest headline of the week goes to The Atlantic:

Climate Change Can Be Stopped by Turning Air Into Gasoline

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.

If their technique is successfully implemented at scale, it could transform how humanity thinks about the problem of climate change. It could give people a decisive new tool in the race against a warming planet, but could also unsettle the issue’s delicate politics, making it all the harder for society to adapt.

Their research seems almost to smuggle technologies out of the realm of science fiction and into the real. It suggests that people will soon be able to produce gasoline and jet fuel from little more than limestone, hydrogen, and air. It hints at the eventual construction of a vast, industrial-scale network of carbon scrubbers, capable of removing greenhouse gases directly from the atmosphere.

The underlying article that triggered the story has nothing to do with turning CO2 into gasoline. It’s purely about lower-cost direct capture of CO2 from the air (DAC). Even if we assume that the article’s right, and DAC is now cheaper, that in no way means “climate change can be stopped.” There are several huge problems with that notion:

First, if you capture CO2 from the air, make a liquid fuel out of it, and burn that in vehicles, you’re putting the CO2 back in the air. This doesn’t reduce CO2 in the atmosphere; it just reduces the growth rate of CO2 in the atmosphere by displacing the fossil carbon that would otherwise be used. With constant radiative forcing from elevated CO2, temperature will continue to rise for a long time. You might get around this by burning the fuel in stationary plants and sequestering the CO2, but there are huge problems with that as well. There are serious sink constraint problems, and lots of additional costs.

Second, just how do you turn all that CO2 into fuel? The additional step is not free, nor is it conventional Fischer-Tropsch technology, which starts with syngas from coal or gas. You need relatively vast amounts of energy and hydrogen to do it on the necessary gigatons/year scale. One estimate puts the cost of such fuels at $3.80-9.20 a gallon (some of the costs overlap, but it’ll be more at the pump, after refining and marketing).

Third, who the heck is going to pay for all of this? If you want to just offset global emissions of ~40 gigatons CO2/year at the most optimistic cost of $100/ton, with free fuel conversion, that’s $4 trillion a year. If you’re going to cough up that kind of money, there are a lot of other things you could do first, but no one has an incentive to do it when the price of emissions is approximately zero.

Ironically, the Carbon Engineering team seems to be aware of these problems:

Keith said it was important to still stop emitting carbon-dioxide pollution where feasible. “My view is we should stick to trying to cut emissions first. As a voter, my view is it’s cheaper not to emit a ton of [carbon dioxide] than it is to emit it and recapture it.”

I think there are two bottom lines here:

  1. Anyone who claims to have a silver bullet for a problem that pervades all human enterprise is probably selling snake oil.
  2. Without a substantial emissions price as the primary incentive guiding market decisions about carbon intensity, all large scale abatement efforts are a fantasy.

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