Even if the world manages to keep global warming at 2 degrees Celsius — the goal of the Paris climate agreement — consequences will be severe.
It’s past time to start investing in technology to suck carbon out of the atmosphere — at the source of carbon emissions, and, ultimately, directly from the air. There have been enough small-scale demonstrations that show so-called carbon capture can work, and enough independent reports showing that we can’t avoid dangerous global warming without it. The technology won’t go far without government help: subsidies, infrastructure investments and policy changes that would make carbon capture schemes potentially profitable.
The downside is that people may hold out the possibility of carbon capture as a reason to delay cutting emissions, as a spokesperson for the coal industry did this week in a New York Times story about the latest report from the U.N. climate panel. What’s become clear in the last few months is there’s no choice between eliminating the dirtiest fuels and enacting carbon capture. We’ve got to do it all, now: phase out coal, move to renewables and capture carbon.
The new report from the Intergovernmental Panel on Climate Change asserts that even if the world manages to keep global warming at just 2 degrees Celsius — the goal of the Paris climate agreement — there will be dire consequences, including crop failures and sea level rise. The committee recommends avoiding warming beyond 1.5 degrees Celsius (2.7 Fahrenheit) above pre-industrial levels. (According to climate models, business as usual will lead to a rise of 4 degrees Celsius [7 degrees Fahrenheit], or maybe more, by the end of the century.)
Cutting emissions won’t be enough. This piece in Vox examines three roadmaps that different scientific groups have created for achieving less than 1.5 degrees of warming. Two of them conclude that it’s impossible without carbon capture. The other concludes that it might be possible if everything else goes perfectly.
There have been some exciting advances in carbon capture technology. In June, Harvard scientist David Keith announced that with a pilot plant in Canada, he’d developed a system for capturing carbon directly from the atmosphere, and that it would cost a fraction of previous estimates.
The plant uses big fans and chemical reactions to concentrate carbon, which is then used to make synthetic fuels — diesel, gasoline and jet fuel. That might be used for aviation or other applications that can’t be easily converted to electricity. His findings, which he published in a new energy journal Joule, led to celebratory coverage in the Atlantic and a more low-key but still positive story in Science.
When I spoke to Keith, he said that while he’s optimistic about the technology, the headlines may have confused some people into thinking this technology would develop without any regulatory help. He cited a piece in the Federalist, for example, in which the author interpreted the advance to mean that “innovation” had won out over, “widespread state-compelled behavior modification or top-down economic regimes.”
That’s a misreading of the situation, Keith said. We still need the government to compel some behavior or there would be no incentive to develop his innovation. As the piece in Science noted, the one place where carbon capture has a chance to flourish is California, thanks to the state’s regulations that increasingly require “low-carbon” fuels. The synthetic fuels produced from captured carbon would qualify as zero carbon.
Another system, carbon capture utilization and storage, is up and running in a few places. In a paper published last month in the Proceedings of the National Academy of Sciences, Princeton University environmental engineers Ryan Edwards and Mike Celia made a case that the technology could make a significant dent in carbon emissions. They proposed a plan for capturing carbon from ethanol refineries in the Midwest — where the emissions are primarily made up of carbon dioxide.
Then a pipeline could transport it to Texas, where there’s a market for it in enhanced oil recovery. That may seem counterproductive since the oil will go on to be burned and emit carbon, but in Edwards’s calculations, this is tiny compared to the amount of carbon captured from the ethanol plants.
The scheme is a variation on a strategy known as bioenergy with carbon capture and sequestration, which has been controversial among scientists. As critics point out in this piece for MIT Technology Review, such a system requires land for growing plants; fertilizer; and energy to farm and transport the crops. And there’s always the possibility that it won’t work.
But it’s another matter to capture carbon that would be emitted otherwise, and Edwards said it’s a good way to clean up high-emission industries such as ethanol, steel and cement. The amount of carbon captured has to start out small, but people will learn, and the technology will advance.
All these schemes hold out the promise of negative emissions — a seemingly magical feat of reversing some of the damage done to the atmosphere. That would happen if the captured carbon were injected deep into the ground, rather than put to use. Decades from now people may be doing this on a big enough scale to matter, but first they have to get a lot better at capturing carbon. Smaller projects are the only way to start. That’s where they can learn, and the costs can come down, Edwards said: “Getting started now is really important.” – Bloomberg