The ocean plays an important role in regulating the amount of carbon dioxide in the atmosphere. As atmospheric concentrations of carbon dioxide rise (see the Atmospheric Concentrations of Greenhouse Gases indicator on p. 16), the ocean absorbs more carbon dioxide. Because of the slow mixing time between surface waters and deeper waters, it can take hundreds to thousands of years to establish this balance. Over the past 250 years, oceans have absorbed approximately 40 percent of the carbon dioxide produced by human activities.

ECOA-4 mission samples most northern line ever
The fourth East Coast Ocean Acidification cruise completed the first leg sampling the most northern line ever.




