Maybe it is my age, but I can remember when the ozone hole was considered to be a major environmental issue. However, these day it hardly gets a mention, it has rather dropped from public awareness. The trouble is the problem of the ozone hole hasn’t gone away, it is still every much with us! Today being the International Day for the Preservation of the Ozone Layer I though I should publish something here.
The ozone hole is often thought of as being a southern hemisphere problem. It is well known that there have been a marked increase in malignant melanomas in people living in Australasia over the last twenty years. This believed to be linked to the thinning of the ozone layer which allows increasing amounts of damaging ultraviolet light to reach the surface of the planet.
In order to try and deal with this problem the Montréal protocol was signed on this day in 1987. This lead to banning the use of Chlorofluorocarbons (CFCs) and the slow phasing out of Hydrochlorofluorocarbons (HCFCs), the Montreal Protocol has often been called the most successful international environmental agreement to date, with a 2001 NASA report showing the ozone thinning over Antarctica had remained the same thickness for the previous three years.
However, in subsequent years the size of the hole has been seen to fluctuate and it is still very much with us:
This is a view of ozone concentration over the Antarctic today.
Seeing such an image it is all too easy to think of this as being a problem for the southern hemisphere and not something that will directly effect us in the northern hemisphere. This is not the case, observations from Northern Canada have shown the largest ozone loss over high northern latitudes following the coldest winter yet seen in the Arctic stratosphere.
This is a view of ozone concentration over the Arctic today.
So, as you can see there is no reason to be complacent about this issue, it is still with us and it is one that is not going away. It should also come as no surprise that the rates of skin cancer (malignant melanoma) is also on the rise in the northern hemisphere, just something to think about.
Monday, 19th, September 2011 at 15:19
“However, in subsequent years the size of the hole has been seen to fluctuate and it is still very much with us:”
That’s because there’s a 200-year lag between the stopping of CFC use and ozone recovery.
“The scientific consensus of researchers in this field is that we should immediately stop producing ozone-depleting chemicals. Even with immediate action, models indicate that it will take 50-60 years for the ozone layer to return in 1975 levels and another 100-200 years for full recovery to pre-1950 levels.”
http://www.admwebstudios.co.uk/Atmosphere5.htm
I’m guessing you know about the circumpolar vortex, the wind that prevents ozone produced near the equator being carried to the South Pole by high-altitude winds, but which is much less virulent in the northern hemisphere due to the greater land mass?
Monday, 19th, September 2011 at 15:59
Thanks for your comments Tim, maybe I should have spent some more time researching the details before posting, but my main purpose with this post is to remind people that this is a problem which hasn’t gone away and will be with us for a long time to come. All to often I hear people saying that we don’t need to worry about environmental problems because “scientist will find a solution”. Sometimes we can find ways to fix things, but these solutions as never instant, it is far better not to break things in the first place. While many industries may think that environmental protection is some sort of luxury, when the full cost are looked at it is far cheaper than the alternative. The environment doesn’t take prisoners…