As “Clean Coal” Falters, Remember Safe, Cheap Carbon-Capture Already Exists

July 07, 2016

A showpiece “clean coal” project in Kemper Country, Mississippi is three years behind schedule, four billion dollars over budget, faces swirling allegations of contracting scandals and shoddy construction, and has yet to capture or store any carbon, as brought home on Tuesday by a 5000-word exposé in the New York Times. Whenever I read articles about Southern Company’s “clean coal” boondoggle (Grist and Politico published similar exposés in recent years), I remember that safe, cheap, natural carbon-capture-and-storage (CCS) is already available at large-scale—in the form of forests. In fact, this is one of the key messages in our forthcoming book, Why Forests? Why Now? to be published later this year.

So, why forests, why now? Let’s look at the facts.

Safe. There are hardly any good places to put carbon dioxide. Excess carbon dioxide in the atmosphere is unsafe because it causes climate change. Around one-quarter of carbon dioxide emissions end up in the ocean; this is unsafe too because it acidifies the sea, dissolving the shellfish and corals on which much of humanity depends for food. Storing carbon dioxide in underground rock formations, as envisioned at Kemper, is still risky and unproven. Turning carbon dioxide into solid rock, as recently achieved in Iceland, sounds extraordinarily promising, but has a long way to go before it’s ready for prime time. However, storing carbon in the living biomass of forests and other ecosystems is not only safe but provides many side-benefits for health, water, electricity, and agriculture.

Natural. Recall that as trees and other plants grow, they absorb carbon dioxide from the air and turn it into solid carbon. This process—photosynthesis—has been honed to perfection over millions of years. Even mature forests absorb carbon dioxide, socking it away as carbon in the soil as shown in the figure below. One logical way to fight climate change is to accelerate this process by protecting and restoring forests, but we’re still doing the opposite, clearing a Maine-sized area of tropical forests every year.

Available at large scale.
No action can stop climate change single handedly—not “clean coal,” not forest conservation. Still, the potential to fight climate change by protecting and restoring tropical forests is vast. Halting and reversing tropical deforestation could counteract up to 24-30 percent of annual greenhouse gas emissions.

Cheap. While “clean coal” might cost more than $100 per ton of avoided carbon dioxide emissions, preventing deforestation can protect the climate at far lower cost. Paying farmers in Uganda to keep trees standing costs less than $1 per ton of avoided emissions, according to a new NBER working paper. An avoided-deforestation project in Alto Mayo, Peru costs $2-3 per ton, according to its proponents.[i] And bilateral agreements with Brazil and Guyana have cost the government of Norway $5 per ton. (These latter government-to-government agreements are most similar in form to the UN-agreed mechanism for reducing emissions from deforestation, or REDD+.)

Match spending to opportunity. I’m of two minds about “clean coal.” On one hand, rapidly growing economies in India, Indonesia, and elsewhere are heavily reliant on coal, while China is trying to wean itself off coal-dependency. If “clean coal” ever actually existed it would do a world of good in enabling these countries to develop without crippling air pollution.

On the other hand, it’s folly to spill so many billions on a longshot technology that might never see the light of day while letting a safe, cheap, natural, available source of carbon-capture-and-storage starve for cash. Funding “clean coal” or funding forest conservation is not an either-or choice, of course; I’d just like to see each funded at a scale commensurate with its respective opportunity.

As US taxpayers, let’s spend more on protecting tropical forests than we spend cushioning Southern Company from cost overruns at Kemper.

[i] Agustin Silvani, Conservation International, Personal Communication, May 25, 2015.


CGD blog posts reflect the views of the authors, drawing on prior research and experience in their areas of expertise. CGD is a nonpartisan, independent organization and does not take institutional positions.