Earth facing a slow death?

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24/10/2000 14:36 - (SA) Earth facing a slow death?

Wolfram Zwecker

Johannesburg - During the first few months of the year the ozone hole over Antarctica grew to a frightening 24 million square metres or the equivalent of three times the size of the United States and scientists warn that the coming ten years are of crucial importance.

This decade would be an indication whether the destruction has reached a peak and has turned around - or that earth is facing a slow death.

It is not clear exactly when it was first discovered that a thinning of the ozone layer was taking place. It is known that sometime in the 1970s a team of British scientists based in Antarctica were the first to research the phenomenon.

These scientists were reportedly so shocked by their first findings that they would not believe them.

They replaced their equipment and sent the rest in for "repairs". However readings taken the following summer confirmed the previous findings and were even worse: not only was the ozone hole over Antarctica huge, but it was expanding.

This month it was announced that the hole - the area where no ozone is present - had reached record proportions: that an area three times the size of the United States could fit into it.

Shortly after the announcement a warning was issued to people living in the south of Argentina: don't go out into the sun, you could receive serious sunburn in seven minutes - and suffer even more serious consequences.

Concerns are increasing because of the serious consequences the ozone hole poses for humans and animals.

The United Nations Environmental Programme (Unep) issued a report in 1998 after years of research and observation of the phenomenon that still serves as a guideline to measure new trends.

The discovery of the ozone hole resulted in an entire series of agreements all aimed at reducing chlorofluorocarbon (CFC) emissions that damage the ozone layer.

To put it plainly: the ozone layer offers protection against damaging ultra-violet rays. CFCs released as a result of human activities in some instances react to ice clouds over Antarctica during late winter. This results in a unique chemical reaction that destroys ozone molecules.

Ultra-violet rays are then able to reach earth "unobstructed", with far-reaching consequences only noticed or felt a few years down the line. As for example people who are exposed only develop skin cancer or cataracts much later.

The human skin and eyes are directly exposed to sunlight.

Eye cataracts generally develop for a variety of reasons. The incidence among people older than 30 increases tenfold each year. As a result of the hole in the ozone layer, however, the predictions are that this increase could occur ten years earlier - that just as many cataract victims would be under the age of 30 as are currently over the age of 40.

In cases where ultraviolet rays were diagnosed as the cause of cataracts, it often is directly related to "sun burn" inside the eye when the rays damage the lens, retina and cornea. However, cataracts are among many eye problems that can develop. Chances that just about all of the eye's tissue is damaged, increases dramatically where ultra-violet rays are involved.

One study found that children younger than five years of age were 36 times more likely to develop eye problems where these conditions were prevalent.

The ozone hole also poses added problems for HIV/Aids sufferers as research suggest that there is an abnormal increase in the incidence of cataracts and other eye problems among them.

Skin cancer is the most general form of cancer among people with lighter skins and the cause is directly linked to sunlight exposure. Sunlight also causes premature ageing of the skin. This ageing process is predicted to speed up and the incidence of skin cancer will increase markedly as a result of the ozone hole.

Animals experience more or less the same problems as humans, with eyes and skin coming under the heaviest attack. In the Andes mountains in Chile cases of animals with eye problems have been reported. Research is being conducted to determine whether these problems resulted exclusively from the ozone hole or whether the hole is a contributing factor.

The ozone hole will cause problems in the environment as well, with the difference that plants and micro-organisms have mechanisms to defuse or deflect the effects of ultra-violet rays.

Research suggests that ultra-violet rays might alter gene composition in an organism rather than damaging it. In other words, the gene changes and acquires new "defence" characteristics against the damaging rays.

In more advanced plant species increased ultra-violet means that they are "weakened", becoming more susceptible to diseases.

Studies have also shown that effects of ultra-violet are stored and passed on from one generation to the next.

The marine environment also faces threat from the ozone hole. Phytoplankton, for example, which forms the basis of the food chain, is seriously affected as its growth, photosynthesis, protein and pigment content as well as it reproductive processes are influenced.

The most severe problems in the sea are expected to occur directly under the hole in the Antarctica area - the nursery of several fish species that are a natural resource for humans.

All these problems resulting from a thinning in the ozone layer will also impact on global warming since more carbon dioxide is present in the atmosphere, which aggravates the greenhouse effect.

Scientists hope that attempts at saving the situation would result in a stabilisation of the hole within the next ten years and would effect a "cover up" over a period of 100 years.

One factor which could wreck these efforts is a huge volcanic eruption - and such an event is in fact predicted within the next ten years.

During a serious volcanic eruption enough harmful elements are emitted to render all human efforts at saving the ozone layer and restoring earth's "health graph" to "normal" null and void.

http://news.24.com/News24/Technology/Science_Nature/0,1113,2-13-46_930681,00.html



-- Martin Thompson (mthom1927@aol.com), October 24, 2000


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