Ozone Layer Depletion and Global Warming
OZONE LAYER
DEPLETION AND
GLOBAL WARMING
OZONE LAYER DEPLETION AND GLOBAL WARMING.
The ozone layer acts as a giant sunshade, protecting plants and animals from much of the sun’s harmful ultraviolet radiations.
Ozone forms a layer in the stratosphere, 15-40 km above the earth surface. If the ozone in the atmosphere from the ground level to a height of 60 km could be assembled at the earth’s surface, it would comprise a layer of gas only about 3mm thick.
Global stratospheric ozone levels have declined, which means that the ozone layer is changing. Stratospheric ozone has large natural temporal and spatial variations, up to 30 % variation may be regarded as normal. However, we now have evidence of significant thinning of the ozone layer during spring and summer. This is observed in both the Northern and the Southern hemispheres at middle and high latitudes. During the last 10-15 years, the ozone layer above the Northern hemisphere has been reduced by 5-6 % in spring per decade. The latest tests (January- March 1995) have shown very large reductions, with maximum of more than 30 % reduction compared to normal.
UV RADIATION:
A depletion of the ozone layer will increase the UV- radiations at ground level. Increasing doses of UV-B may cause skin cancer, eye cataracts, damage to the immune system in animals as well as human beings, and have an adverse impact on plant growth.
The UV index developed by Environment Canada. It runs on a scale from 0 to 10 being a typical mid summer, sunny day in the tropics. A relative scale ranging from low to extreme is also applied: In extreme conditions ( UV Index higher than 9) light, sensitive and un tanned skin may burn in less than 15 minutes.
UV radiations will affect human health through for example sunburn, snow blindness, other eye damage, early aging of the skin and rising rates of skin cancer. It may also cause suppression of the immune system. It will like wise affect the productivity of the
DEPLETION AND
GLOBAL WARMING
OZONE LAYER DEPLETION AND GLOBAL WARMING.
The ozone layer acts as a giant sunshade, protecting plants and animals from much of the sun’s harmful ultraviolet radiations.
Ozone forms a layer in the stratosphere, 15-40 km above the earth surface. If the ozone in the atmosphere from the ground level to a height of 60 km could be assembled at the earth’s surface, it would comprise a layer of gas only about 3mm thick.
Global stratospheric ozone levels have declined, which means that the ozone layer is changing. Stratospheric ozone has large natural temporal and spatial variations, up to 30 % variation may be regarded as normal. However, we now have evidence of significant thinning of the ozone layer during spring and summer. This is observed in both the Northern and the Southern hemispheres at middle and high latitudes. During the last 10-15 years, the ozone layer above the Northern hemisphere has been reduced by 5-6 % in spring per decade. The latest tests (January- March 1995) have shown very large reductions, with maximum of more than 30 % reduction compared to normal.
UV RADIATION:
A depletion of the ozone layer will increase the UV- radiations at ground level. Increasing doses of UV-B may cause skin cancer, eye cataracts, damage to the immune system in animals as well as human beings, and have an adverse impact on plant growth.
The UV index developed by Environment Canada. It runs on a scale from 0 to 10 being a typical mid summer, sunny day in the tropics. A relative scale ranging from low to extreme is also applied: In extreme conditions ( UV Index higher than 9) light, sensitive and un tanned skin may burn in less than 15 minutes.
UV radiations will affect human health through for example sunburn, snow blindness, other eye damage, early aging of the skin and rising rates of skin cancer. It may also cause suppression of the immune system. It will like wise affect the productivity of the