There are a lot of ways to capture and sequester carbon dioxide, many of them familiar: for example, trees - when viewed through the climate lens - are small, distributed carbon sequestration vehicles that soak up CO2 and store it as wood. Other approaches include sprinkling iron in the ocean to cause algae blooms, turning agricultural and forestry wastes into biochar, or growing carbon-neutral biofuel crops (assuming there is such a thing).
But the biggest potential bang - and the biggest focus - has been on pumping CO2 directly underground from coal-fired power plants and similar industrial facilities. Sounded like a great idea, until today:
A stadium-size sinkhole that formed in south Texas's oil country this month is renewing questions about the effects of billions of barrels of saltwater injected into the ground each year as a byproduct of oil and gas drilling. ...
State regulators haven't yet decided what caused the sinkhole. But Donald Van Nieuwenhuise, director of the petroleum geosciences program at the University of Houston, believes the most likely cause is that waste water eroded an underground structure called a salt dome, a deposit of compressed salt, and caused the collapse.
As fate would have it, salt domes are the underground structures believed to be best-suited for carbon sequestration - they are (or were) believed to be impermeable, so pumping a lot of CO2 into them seemed like a safe bet. They also happen to be the home of a lot of the world's remaining oil, so the idea was by pumping CO2 into salt domes, you could max out your oil recovery while sequestering carbon.
I hope the geologists get a good look at this sinkhole. If salt domes can't be relied upon for CO2 storage, our problems just got a whole lot worse.
One of the major challenges facing the global energy sector is the amount of time it takes to develop new energy resources. Even if you didn't care about the negative externalities, environmental impacts or climate change contributions of fossil fuels like coal, oil and natural gas, it takes a long time (and billions of dollars) to drill deep holes, excavate or detonate massive mines, build pipelines and railways, construct power plants and high-voltage power lines ... as a famous recent American President and avowed fossil fuel aficionado likes to say, "It's hard work."