C6 - Atmosphere

What role did volcanos play in the early atmosphere?

volcanoes eruption release carbon dioxide, steam, methane, ammonia, degassing the earth

During the early atmosphere, how did the oceans form?

The water vapour ( produced from steam form volcanoes) condensed forming oceans

during the early atmosphere, how did the amount of carbon dioxide reduce?

• carbon dioxide dissolved in oceans

• Photosynthesis by green plants

• Carbon dioxide eventually got locked up in fossil fuels and sedimentary rocks

During the early atmosphere, what caused the amount of oxygen to increase?

Green plants evolved over earth removing carbon dioxide and producing oxygen

What enabled the evolution of complex organisms?

• Levels of oxygen increased

• Ozone layer created blocking harmful rays

• Carbon dioxide level reduced

What is the composition of today’s atmosphere?

• 78% nitrogen

• 21% oxygen

• 0.04% carbon dioxide

• 1% other gases

Name the greenhouse gases

• carbon dioxide

• Methane

• Water vapour

• Nitrous oxide

Why is the greenhouse effect important?

Helps keep the earth warm

The sun gives out electromagnetic radiation. How does the radiation cause the greenhouse effect?

• most wavelengths from the sun (EM waves) pass through the atmosphere on earth (short wavelength radiation is absorbed)

• The energy absorbed by the earth is emitted into space at a long wavelength (IR radiation)

• Some of the IR radiation is absorbed by green house gases and re-emitted back towards earth.

• This causes the heating of the earth

What is the enhanced greenhouse effect?

Most heat radiated from the earth is re absorbed and less re- emitted into space. This causes atmosphere to heat up.

Which gases is acid rain caused by?

Sulfur dioxide and nitrogen oxide

How is nitrogen oxide formed?

By a reaction between nitrogen and oxygen in the air caused by the heat of burning

Where does sulfur dioxide come from?

The sulfur impurities in the fossil fuel

What happens when the gases produced by combustion mix with clouds?

They form dilute sulfuric acid and nitric acid. This falls as acid rain

What are the problems caused by acid rain?

• lakes become acidic

• Kills trees

• Damages limestone buildings and statues

What is a photochemical smog?

Air pollution caused by sunlight acting on the oxide of nitrogen

What are the effects of ground level ozone?

• Breathing difficulties

• Headaches

• Tiredness

When is carbon monoxide produced?

Incomplete combustion

What are the effects of carbon monoxide?

• stop blood carrying oxygen

• Lack of oxygen causes fainting, coma and even death

What are particulates?

Small pieces of solid caused by incomplete combustion

How can we prevent or slow down climate change?

• Reduce greenhouse gases

• Iimit use of fossil fuels e.g. walk or cycle