What important discovery was made by Columbia University researchers concerning carbon dioxide levels using data from Biosphere 2?
A. The world's ocean can serve as a endless sink of atmospheric carbon dioxide with little effect on biological organisms.
B. Carbon dioxide levels will decrease naturally in both air and water in a contained system such as Biosphere 2.
C. Carbon dioxide in the atmosphere is absorbing atmospheric oxygen.
D. Carbon dioxide in the atmosphere is absorbed into water causing ocean acidification.