What sort of natural variations does the ozone layer show?

Are ozone levels changing?

How is ozone created?

What is the ozone layer?

How and where is ozone measured in the UK?

What are CFC's?

How do CFC's destroy ozone?

Is ultraviolet radiation increasing at the earth's surface?

What is being done about ozone depletion?

How can Chlorofluorocarbons (CFCs) get to the stratosphere if they're heavier than air?

What is the evidence that stratospheric ozone is destroyed by chlorine and bromine?

Does most of the chlorine in the stratosphere come from human or natural sources?

Can natural changes such as the Sun's output and volcanic eruptions be responsible for the observed changes in ozone?

When did the Antarctic ozone hole first appear?

Why has an ozone hole appeared over Antarctica when CFCs and halons are released mainly in the Northern Hemisphere?

Is there an ozone hole over the Arctic?

Is the depletion of the ozone layer leading to an increase in ground-level ultraviolet radiation?

Does ozone depletion cause climate change?

How severe is the ozone depletion now?

Is the ozone layer expected to recover? If so, when?