Adding lime to oceans ...

You might be considering other options for oceans other than those of the newly announced effort of Shell and its sequestration initiative (C&I 2008, 14, 24). If so the key is to consider being a law abiding citizen, Second Law of Thermodynamics abiding that is. Since adding a base to the acidic ocean is a one to one bit of chemistry, simply determining the mass of limestone mineral to be utilitarian is going to be a real challenge. Consider the fact that the net accumulating surplus of C[O.sub.2] in the air each year is 6-8 gigatonnes, how many gigatonnes of limestone might be utilitarian?

Compare that number with the mass of present global ocean cargos. Putting minerals into the ocean surely is the way to go but the choice is which minerals.

Russ George

Planktos Science, San Francisco, US

Editor's note: A Comment based on this letter by Russ George will appear in a future issue.