Chemical changes in seawater make a key nutrient less available to these organisms
Depending on nature — or at least phytoplankton in the ocean — to absorb humans’ ever-increasing emissions of planet-warming carbon dioxide probably won’t solve the problem, new research suggests.
A few scientists have long argued that increasing CO2 levels will stimulate long-term carbon-sopping plant growth, but the idea hasn’t proven true for land plants (SN: 12/16/00, p. 396). Now, new findings suggest that the notion won’t hold for tiny ocean plants either, thanks to one of the nagging side effects of carbon dioxide emissions — the gradual acidification of the ocean’s surface waters. Research by oceanographer Dalin Shi and his colleagues at Princeton University hints that rising CO2, instead of providing extra nutrients for phytoplankton, may actually curb the growth of these organisms, which form the base of the ocean’s food chain. The team reports these findings online January 14 and in an upcoming Science.