Changes in ocean chemistry
One of the central stressors impacting our oceans today, however, is carbon dioxide—the same gas that is primarily responsible for global warming. UVic’s Dr. Andrew Weaver, one of the authors of the UN Intergovernmental Panel on Climate Change (IPCC) report presented in Paris last month, is passionate and convincing when he says the amount of carbon in our atmosphere now dwarfs anything the Earth has seen in the last 650,000 years.
Weaver says we’re on track to heat up 2.5 – 3° C by 2100, which coincidentally, is the critical threshold for the melting ice sheet that covers most of Greenland. Any warmer, warns Weaver, and the ice sheet is gone.
Stanford University’s Dr. Ken Caldeira says high carbon emissions are essentially killing off coral reefs, although he shies away from predicting their extinction. High carbon levels in the atmosphere combine with water molecules, causing the oceans to become acidic and corrosive to corals. Corals need calcium carbonate to form their shells, but the acidification process takes away the necessary building blocks. Even more alarming, Caldeira says many species of plankton are threatened by ocean acidification because they, too, make calcium carbonate shells. Since they are the first link in the ocean food chain, their disappearance would have dire consequences for entire marine ecosystems.
The Ring, March 2007. Article.
