Much of life on Earth requires oxygen - not only for metabolism, but also for protection. Oxygen, in its many forms, occurs throughout the atmosphere. At 21%, molecular oxygen (O2) is the second most common gas in our atmosphere. At 0.0001%, ozone (O3) is hardly common, but its impact is enormous. Near the ground, in the stratosphere, ozone acts as a pollutant. In the upper atmosphere (troposphere), it acts as a shield, blocking harmful ultraviolet energy from the sun. Much attention has been made to the human-caused deterioration of the ozone layer, and the infamous "holes" that form over the Antarctic each year. The term "hole" is a bit of a misnomer, as an actual hole does not form, the ozone layer just becomes much thinner.
NOAA is one of the global leaders in monitoring and analyzing the ozone layer, and has co-authored the most recent analysis describing the state of the ozone layer . The Scientific Assessment Panel of the U.N. Montreal Protocol on Substances that Deplete the Ozone Layer has found that The Montreal Protocol (enacted in 1987) has been effective in reducing mankind's impact on the ozone layer, but climate change may also begin to show signs of impacting the ozone layer, especially in the Arctic, where climate-induced circulation patterns may become more severe.
This animation uses data from NOAA's satellites to show the annual changes in the size of the Antarctic ozone hole, along with daily fluctuations in global ozone concentration. As pointed out in the report, the size of the Antarctic ozone hole appears to have reached a turnaround point, whereby the hole is not getting worse each year, but at the same time it is not decreasing. It is expected that a return to "normal", pre-1980 levels of ozone will occur later in this century -- that is, if the ban on ozone-destroying chemicals stays in place.
NOAA is one of the global leaders in monitoring and analyzing the ozone layer, and has co-authored the most recent analysis describing the state of the ozone layer . The Scientific Assessment Panel of the U.N. Montreal Protocol on Substances that Deplete the Ozone Layer has found that The Montreal Protocol (enacted in 1987) has been effective in reducing mankind's impact on the ozone layer, but climate change may also begin to show signs of impacting the ozone layer, especially in the Arctic, where climate-induced circulation patterns may become more severe.
This animation uses data from NOAA's satellites to show the annual changes in the size of the Antarctic ozone hole, along with daily fluctuations in global ozone concentration. As pointed out in the report, the size of the Antarctic ozone hole appears to have reached a turnaround point, whereby the hole is not getting worse each year, but at the same time it is not decreasing. It is expected that a return to "normal", pre-1980 levels of ozone will occur later in this century -- that is, if the ban on ozone-destroying chemicals stays in place.
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