Remember in the 1990′s when the totality of the discussion of the environment seemed to be focused on the ozone layer? We’ve come quite a long way since then in many ways, but what remains is the gap in the ozone layer that is apparently not only increasing our chances of over-exposure to the sun’s ultraviolet rays, but also changing the oceans.
Recent studies have found that the Antarctic ozone hole is changing how the water mixes in the Southern Ocean. The westerly winds in the region have grown stronger closer to the earth’s surface and are weakening the Southern Ocean’s absorption of carbon dioxide from the atmosphere. This is significant when you consider that the South Seas are responsible for 40 percent of the total carbon absorbed by the world’s seas, according to the Huffington Post.
Need a little reminder about our history with the ozone? Well, according to NOAA, ozone is a gas that occurs naturally in our atmosphere, mostly concentrated in the ozone layer. One of its most important functions is protecting life forms on earth from ultraviolet light from the sun. The ozone layer has been depleted by man-made chemicals called chlorofluorocarbons (CFCs) such as aerosols, refrigerants, and air conditioners. These chemicals break down the ozone molecules creating holes which allow the ultraviolet rays through.
To protect the ozone layer the 1989 Montreal Protocol was implemented, creating an eventual ban on the use of CFC-12s (chlorofluorocarbons), which cause the ozone layer to thin. One of the most widely ratified international agreements in United Nations history, the ban has reduced the break down of the ozone though a full recovery isn’t expected until 2075.
Meanwhile, the study, which sampled the water in the southern oceans searching for high concentrations of CFC 12 at depths from 200 to 1500 meters, determined that the westerly winds near the ocean surface have strengthened as the ozone layer has thinned over time. In the northern hemisphere ozone levels have been dropping by four percent per decade with over five percent of the earth’s surface being affected by ozone holes.
While our collective consciousness has drifted away from the ozone and on to other matters such as ocean acidification, over fishing and endangered species, the ozone still has an affect on the environment and the ocean. And, with increasing green house gases we must continue our efforts to reduce green house emissions to save the ozone layer.
So much to think about and act on, so little time!