As humans we often find ourselves choosing between two sets of imperfect options. Is it better to be late to the birthday party, or is it better to be on-time (but empty-handed)? Is it worth it to cram yourself onto a packed commuter bus to arrive to work a little earlier — but a lot more frustrated — or should you take your time?
It may be time to apply this thinking to the climate change fight. Some greenhouse gasses are significantly worse than other greenhouse gasses, in terms of how much heat they trap in the atmosphere. If we could turn the worst greenhouse gasses into less-damaging greenhouse gasses, then, we wind up with a net positive.
That’s the counterintuitive proposal from a group of climate researchers at Stanford University who want to turn one of the most insidious greenhouse gases — methane — into carbon dioxide, one of the most common (and still, to be clear, quite bad) greenhouse gasses.
Their thinking is that methane is roughly 84 times more potent than carbon dioxide over the first two decades after it’s released into the atmosphere. Turning all that methane into CO2, then, would still put humanity ahead.
Indeed, they estimate that this transformation would eliminate about one-sixth of the cumulative drivers of global warming.
Their proposal was published Monday in the journal Nature Sustainability.
“We should be putting the same thought and study into removing methane as we are for carbon dioxide,” Robert Jackson, senior fellow at Stanford Woods Institute for the Environment and chair of the Global Carbon Project, tells Inverse. “My goal is to restore the atmosphere, which is a more powerful goal than stabilizing temperatures.”
It Could Actually Be Profitable
There are other reasons why the policy may be worth pursuing. For one, Jackson argues that the practice could be profitable as the market for carbon-offsets — basically where polluters pay non-polluters — grows. The idea is that private industry would set up their own arrays to suck methane out of the air, transform it into CO2 using a catalyst, and then release the CO2 into the air, as opposed to trying to sequester or store it. The firms operating these arrays could then sell carbon offsets to other polluters.
The incentives should get substantial. A single array processing wind at a speed of 20 km per hour and removing roughly 20 percent of the methane in the air would generate between $500,000 and $5 million annually, according to the authors’ estimates, assuming it’s at 90 percent operational capacity.
Why Isn’t This Happening Already?
So why, then, aren’t we doing this already? The problem is two-fold: First governments need to help create a robust enough marketplace for carbon offsets to make private sector investments in this technology viable. This, however, seems pretty likely. As more countries enact emissions caps and other policies, the price for carbon offsets is expected to rise to $500 per ton within the century, up from the $3-$44.80 per ton it is now.
There is also a technological hurdle: Chemists need to figure out which sort of catalyst to use, which may be tricky. Zeolites, a clay-like microporous mix of aluminum and silicon, could work. But while methane traps lots of heat, it is not particularly abundant in the atmosphere, and it’s not particularly concentrated either. Researchers would have to figure out which catalyst to use which could zero in on the tiny little methane particles in the air and convert them into CO2 at meaningful levels.
“The biggest challenge will be finding catalysts that are specific enough to methane but also selective enough to remove it from their air; or we’ll need to concentrate the methane in some way,” Jackson explains. “You might envision putting an array near a land fill, and scrubbing it from the air.”
There are several reasons why this strategy is worth considering, even if it won’t be easy. Lots of methane comes from particularly tough-to-eliminate sources of human emissions, like livestock and rice production, meaning that it may even be worth continuing indefinitely.
“Even if we could restore the atmosphere to pre-industrial levels of methane, we may want to continue this,” Jackson says.
But most importantly, removing the more abundant CO2 from the atmosphere will take more time, and CO2 sticks around in the atmosphere for a lot longer. There are all sorts of efforts underway to deal with the problem of CO2 removal, from carbon sequestration, to converting CO2 into useful forms of fuel, to efforts to simply plant boatloads of trees.
Unfortunately, many of these efforts are also long shots. Starting with the lesser, but more concentrated evil of methane, then, would buy these other crucial projects some much-needed time.
Zeolites and other technologies should be evaluated and pursued for reducing methane concentrations in the atmosphere from 1,860 ppb to preindustrial levels of ~750 ppb. Such a goal of atmospheric restoration provides a positive framework for change at a time when climate action is desperately needed.