Ozone & Greenhouse Effect

What is Ozone?

Ozone is a molecule that occurs in the Stratosphere

Ozone absorbs harmful UV rays from the sun

O3 + uv O2 + O O3

Ozone in the stratosphere protects us from harmful UV radiation

What’s the problem?In the 1970’s a compound called

Chlorofluorocarbons (CFC’s) began to be used.

CFC’s were used in refrigerators, propellants, aerosols, etc.

It was thought that CFC’s were inert until scientists discovered…

CFC’s destroy ozone!

The ozone hole is a place in the lower stratosphere where ozone has been destroyed

Ozone HoleOne molecule of CFC can destroy up to 100,000

molecules of ozone

This has resulted in a hole in the ozone layer above Antarctica

Dangers of Ozone Depletion

When ozone is depleted, harmful uv rays can get through the atmosphere

This makes it much easier to get skin cancer

What has been done?Once it was proven that CFC’s were destroying

ozone, scientists met in Montreal and made the Montreal Protocol

The Montreal Protocol called for a ban of CFC’s and that production of CFC’s be stopped

The Greenhouse EffectSun’s energy (aka-

heat) gets trapped in the troposphereSome radiation that

reaches Earth’s surface is absorbed.

Some energy is reflected.

The Greenhouse EffectReflected heat might

get trapped by carbon dioxide, water vapor, or other gases.

Trapped heat makes atmosphere warmer.

Warm atmosphere reflects heat to Earth’s surface again!

Greenhouse Effect

No greenhouse effect would mean colder than average temps.

Too much, however, can cause a rise in average temps.

Global WarmingGlobal warming IS the rise in average

temps.

Melting ice caps, rising seas, droughts

Global Warming

Probable cause: carbon dioxide

Where does it come from?

Burning of fossil fuels (coal, oil, natural gas)

Greenhouse GasesThe three types of

greenhouse gases are water vapor, carbon dioxide and methane.

They absorb heat energy from the sun in the form of infrared radiation. This keeps the earth warm enough for life to exist.