You probably know that carbon emissions threaten the atmosphere. The Natural Resources Defense Council wants you to look down, too, at the danger faced by the world's oceans.
Since the Industrial Revolution, oceans have absorbed a quarter of the carbon dioxide produced by burning fossil fuels. Ocean acidity levels have risen 30 percent since that time after millions of years of relative stability, according to the film. Without a reduction in carbon emissions, a scientist says in the film, polar seas could be so acidic by mid-century that they will dissolve shells of marine organisms and shellfish.
-- Abby Haight