SPEEDING up part of the ocean’s natural carbon cycle might help slow global
warming. That’s the thinking behind a plan to lock up carbon dioxide from power
plant emissions by mixing the gas with limestone and seawater, and then dumping
it in the ocean.
Carbon dioxide in the atmosphere normally mixes with seawater at the ocean’s
surface to form carbonic acid. From there it is slowly circulated to the sea
floor, where it reacts with sediments to form relatively inert calcium
bicarbonate.
“Naturally, this reaction takes 5000 or 10,000 years,” says biogeochemist Ken
Caldeira of Lawrence Livermore National Laboratory…
