The hole was first observed in the 70s when scientists started to investigate the upper atmosphere. CFCs have almost exclusively been the cause of the 'hole' in the ozone layer.
It's not a hole as such, but an area where the ozone concentration is much lower than the average.
The 'hole' does change shape according to the Sun's sunspot activity, the seasons, and latitude.
This should have all you need to know...
http://www.epa.gov/ozone/science/sc_fact鈥?/a>How long has the 'hole' in the ozone layer existed?
Since flourocarbons became widely used after WWII. I believe that it is fairly constant. The ';breathing'; thing sounds unlikely. It is in the upper atmosphere, and the analogy has no application.
Does it still exist?
It used to be the biggest issue around 10 years ago. But now its never even mentioned.
Strange that.
I wonder if it will be the same for CO2 in the next 10 years?
1870's - 80's. Scientists really started to talk about it in the 80's, although there were some talks on it beforehand. Chloro-Fluoro-Carbons or CFC's cause the problem, and it is a bit of a problem for us, to be honest. The ozone layer is there to protect us from harmful ultraviolet rays from the Sun. With a hole in it, a lot more of these rays get through and burn people alive! Literally. Ozone is a molecule formed of three Oxygen atoms and at our level, where we live, it is considered pollution and many people can get asthmatic reaction. So ozone gets formed down here at our level, where it shouldn't be, while up in the sky there's a massive great big hole! It's not a breathing hole, the ozone layer should be intact.
In 1985 the british antarctic survey team announced some disturbing information that the stratospheric ozone concentration was decreasing over the south pole. The ozone depletion has been happeing at least since the 1960s and possibly a bit earlier.
The discovery was made by accident, American atmospheric analytical methods were programmed to ignore small changes in ozone levels and the changes were considered erroneous. The British scientists looked at the data collected and luckily identified the problem.
Good news is that the ozone layer will repair its self over time now that cfcs are controlled.
a long time
No comments:
Post a Comment