There's no word for the sound you hear upon opening a can of soda. But the tchk-ptoop-fshchss! of a top being popped is distinctive, immediately recognizable. It is the sound of carbonation — or CO2 — rushing from the can. And it's a sound that brings to mind a technology, much overlooked in the popular press, that could safely recapture and store much of that emitted carbon, and has the potential to prevent an impending climate catastrophe.
The CO2 in carbonated drinks is the same CO2 that is spewed from tailpipes and power plants and causes global warming. In fact, the CO2 that makes the bubbles in your soda comes from those same power plants. Instead of being released into the atmosphere as a global-warming gas, the CO2 is captured from power plant exhaust, purified and sold to the nation's bottlers and soft drink fountain suppliers. When you pop the tab, however, the CO2 escapes into the atmosphere anyway.
But there's a silver lining. The same process that captures CO2 from power plants to make drinks fizzy is the one half of a process that has the potential to capture and stash as much as 90% of all CO2 from coal-burning power plants. Engineers and scientists are working on several ways to catch the carbon, either before or after coal burns. One technology known as integrated gasification combined cycle, or IGCC, would turn the coal into gas before it's burned for energy; gasifying it releases the carbon for capture, transportation, and sequestration deep underground. Another process, called "oxy-coal" combustion, removes nitrogen from air before combustion; when coal is burned, the waste gas is close to pure CO2, which can be easily captured.
Scientists and engineers hope to pump this captured carbonation through mile-long straws that reach deep into the Earth's crust, into salt mines, aquifers and oil fields. Underground, the pressure will liquefy it and perhaps eventually turn it to rock. Think of it as "geo-bottling" — except we never want to pop the cap. From Houston to Huainan, scientists are already digging holes and pumping down CO2 by the ton. "The carbon belongs underground," Susan Hovorka, a geologist at the University of Texas, Austin, told one of us in 2005. "I say, put it back."
Today, the CO2 captured for producing soda is only a very small percentage of the total CO2 from power plants, but the technology for large-scale carbon capture and storage looks to be just around the corner. Spurring action from industry and governments has proved difficult, however, because the long-term economic, social and environmental costs of CO2 pollution are not included in the price we pay for energy. That makes CO2-intensive sources of energy like coal-fired power plants look like a better deal than cleaner technologies. But the truth is, it's a "pay me now, or pay me later" situation. In the context of climate change, it's more like, "pay me now, or your kids will pay me even more later."
Fortunately, a combination of efficient markets and smart policy could level the playing field. A carbon-storage industry will be virtually impossible without a national policy that puts a price on CO2 pollution. One such policy involves the creation of a national cap for greenhouse gas emissions and an accompanying market for tradable carbon emission credits. This summer, the U.S. Senate will likely consider legislation that would set up such a market. By making carbon a pollutant and unleashing market forces to find a price for it, the nation will essentially be revealing fossil fuels' true social cost — and giving cleaner technologies, including carbon capture and storage, a fair shot.
Even before the federal government creates a national cap — which is generally considered inevitable — the economy will need a bridge, economic nudges, so that the private sector can test carbon capture and storage before scaling it up. More than 30 states are looking at legislation that would give carbon storage technology a boost. Some call for comprehensive studies of the technology, while in Wyoming — one of several states identified as having underground carbon storage potential — laws are already being written to address questions about ownership of and liability for the underground CO2 vaults. These laws will help U.S. "geo-bottling" incubate while the federal government catches up to state and private efforts. At Duke University's Climate Change Policy Partnership, for example, researchers are modeling optimal routes for gas pipelines, based on engineering, social and environmental factors, to move the CO2 from plant to storage site.
There is little doubt that we'll need help from many new technologies to fight the inexorable rise in greenhouse gas emissions. And indeed, reversing emission trends is truly an all-hands-on-deck affair. But to achieve the targets talked about in current legislation — and notably by each of the presidential candidates — reducing carbon from our power production has to be disproportionately responsible for overall progress. If thorny questions surrounding carbon capture and storage are not answered, and if the technology is not implemented soon, we will have lost precious time in the quest to ward off irreparable consequences of climate change.
Today we bottle CO2 to make soda. Tomorrow we need to be bottling industrial carbon on a grand scale. It's something to think about when you take a soda break on this Earth Day. Pop the tab — tchk-ptoop-fshchss! — drink, think, and, of course, don't forget to recycle.
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