Every spring, a hole as big as the USA develops in the ozone layer over Antarctica, in the South Pole. A smaller hole develops each year over the Arctic, at the North Pole. And there are signs that the ozone layer is getting thinner all over the planet.
Scientists have discovered that the ozone hole over Antarctica started in 1979, and that the ozone layer generally started to get thin in the early 1980s.
The loss of the ozone layer occurs when more ozone is being destroyed than nature is creating.
WHAT CAUSES THE OZONE HOLE?
One group of gases is particularly likely to damage the ozone layer. These gases are called CFCs, Chloro-Fluoro-Carbons.
CFCs are used in some spray cans to force the contents out of the can.
They are also used in refrigerators, air conditioning systems and some fire extinguishers. They are used because they are not poisonous and do not catch fire.
Most countries have now stopped using new CFCs that can be released into the atmosphere, but many scientists believe we must stop using old ones as well.
THE OZONE HOLE AND OUR HEALTH
The ozone layer is like a sunscreen, and a thinning of it would mean that more ultra-violet rays would be reaching us.
Too many UV rays would cause more sunburn, and because sunburn causes skin cancer, this too would increase deaths.
These UV rays are also dangerous for our eyes and could cause an increase in people becoming blind. That is why sun cream and sunglasses are very important.
NOW YOU CAN DO THIS TEST
I this link you can do a test about meteorological instruments
After that you can do this test. You must write the name of the main meteorological instruments.
Now you are going to do the first test of the Unit 3
You have 12 minutes to do it. You must read the questions very carefully and pay attention before wrtiting the answer