Is climate change choking our oceans?

by Matthew Wagstaff

Hiding away in the ocean section of the new IPCC report is a lesser known result of global climate change, ocean deoxygenation.  Many effects of climate change such as increasing global temperatures, rising sea levels and ocean acidification are already well-known and somewhat in the public eye, however there are many other effects that are less well-known and less understood. Deoxygenation of the oceans is one of these lesser-known effects and is being caused by a number of factors. While the acidification of the ocean is caused by the uptake of carbon dioxide from the atmosphere, the deoxygenation of the ocean is mainly due to the increasing temperatures of the surface waters, which has two effects: the solubility effect and the stratification effect. From the IPCC report:

  “It is very likely that global warming will lead to [further] declines in dissolved O2 in the ocean interior through warming-induced reduction in O2 solubility and increased ocean stratification. This will have implications for nutrient and carbon cycling, ocean productivity and marine habitats (Keeling et al., 2010).” Continue reading