From a colleague at SOPAC:
For those interested in marine science, climate change, emission reduction, energy and building aggregates (which I think means all of us!) you may find the following story and links interesting;
…Constantz realized that cement manufacturers, by emulating coral, could meet that demand even as they actually reduced the total amount of carbon dioxide released into the atmosphere. Moreover, they could sequester the raw materials from the world’s single largest carbon-dioxide emitter, electric power plants. In 2009 his latest company, Calera, started putting that insight into practice at a 1,000-megawatt power plant in Moss Landing, California. Engineers there spray mineral-rich seawater or brine water through flue gas captured from the plant’s smokestacks. The calcium in the water bonds with carbon in the would-be pollution to form cement. Constantz says the demonstration plant is capable of producing up to 1,100 tons of cement a day and, in doing so, sequestering 550 tons of carbon dioxide. Within three years, he says, Calera will be operating plants in Australia and Wyoming.
Constantz notes as well that, unlike other sequestration schemes, his plan for capturing carbon emissions is proven. For at least 600 million years, sea creatures have been “sequestering” carbon dioxide in their skeletons, which have compacted over time to form all the limestone on Earth—the very stuff we now heat to make cement. Instead of turning stone to carbon dioxide, we can turn carbon dioxide into “stone,” locking it away forever in the concrete foundations of our cities. “When we think of climate change,” Constantz says, “the main lever we have is putting carbon back in the geologic record.”