hide and secrete?

The on-line version of Scientific American posted this fascinating news item July 14:

Volcanic rocks deep beneath the sea off the coast of California, Oregon and Washington State might prove one of the best places to store the carbon dioxide emissions that are causing global warming, a new study finds. In fact, the very instability that causes earthquakes and eruptions adds an extra layer of protection to keep the CO₂ from ever escaping.

The U.N. Intergovernmental Panel on Climate Change (IPCC) and other experts, including the G8 (Group of Eight) leaders of the world's richest nations, have called carbon capture and storage a critical tool in the fight against climate change. In essence, such technology catches the CO₂ and other pollutants emitted when coal or other fossil fuels are burned. It is then compressed into a liquid and, theoretically, pumped deep beneath the surface to be permanently trapped.

Such technologies have been demonstrated on a small scale to enhance the recovery of oil from tapped out fields; pumping down the CO₂ pushes up more of the black gold. But geophysicist David Goldberg of Columbia University's Lamont–Doherty Earth Observatory in Palisades, N.Y., and his colleagues found that pumping such CO₂ into basalt rock beneath the ocean floor might be a better solution.

Specifically, liquid CO₂ is heavier than the water above it at 8,850 feet (2,700 meters) or more under the surface, meaning any leaks would never bubble back into the atmosphere. Further, the CO₂ mixes with the volcanically warmed water below the surface and undergoes chemical reactions within the basalt (the black rock created from rapidly cooling lava) to form carbonate compounds—otherwise known as chalk—effectively locking up the greenhouse gas in mineral form. The 650-foot (200-meter) layer of marine sediment on top of the basalt rock acts as yet another barrier. "You have three superimposed trapping mechanisms to keep your CO₂ below the sea bottom and out of the atmosphere," Goldberg says. "It's insurance on insurance on insurance."

This is a great solution IF we want to keep mining, digging and burning fossil fuels. The question is, do we? Why spend all this money on the excavation of fossil fuels, the degradation of the environment (especially with the extraction of coal) and then the cost of sequestration, all for a time-limited and volume-limited commodity when we could put that creative energy, money and public support behind renewable energies?

Clearly, no one technology is going to be the be-all-and-end-all solution, so sequestration might be one part of the solution. But we have to keep the other renewable options on the table, moving forward and well-funded and publicly supported.

Enjoy this fabulous summer weather!