We’ve heard a lot lately about the relationship between global warming and the ocean. An article in Thursday’s Journal of Science describes how aquatic dead zones — or hypoxic waters — create trouble for more than the organisms that live in the waters. In addition to their low levels of oxygen killing off marine life, they can also increase global warming. University of Maryland Center for Environmental Science oceanographer Dr. Lou Codispoti explains in his article how waters with depleted oxygen create high levels of Nitrous Oxide which can seep into the atmosphere and add to the greenhouse gas effect.
Aquatic dead zones can be caused naturally but more often than not they are the result of humans polluting the waterways. They have long been the concern of scientists and environmental activists because of the loss of aquatic life. They are difficult to rehabilitate and are often exacerbated by storms that cause runoff of pollutants from the land into the water. As oxygen levels in the water decrease production of nitrous oxide increases. Nitrous oxide is 300 times more potent as a greenhouse gas than carbon dioxide.
It turns out that most of the research done on aquatic dead zones focuses on loss of plant life and the immediate environmental impacts including water safety and beach pollution. There’s not a lot of research done on the rise of nitrous oxide in hypoxic waters and Dr. Codispoti warns that, “we should intensify our observations of the relationship between low oxygen concentrations and nitrous oxide in coastal waters.” As aquatic dead zones around the world intensify on a daily basis the increase in nitrous oxide production could be deadly to the atmosphere.
+ Center for Environmental Science at the University of Maryland
+ Information on Aquatic Dead Zones
Via Science Daily
Great article.
How can these scientists predict the climate in 40 years time, when there is so much that is unknown ? Surely they should base any assumptions on things that can be measured, such as a rise in sea levels. After all, surface temperatures go up and down, but the rise in sea levels reflects both melting ice and thermal expansion.