C13

Question 1

What is the earths atmosphere made of and their %s?

Answer 1

Nitrogen= 78%
Oxygen= 21%
Argon=0.9%
Carbon Dioxide = 0.04%
+trace amounts of other gases

Question 2

What was the earths early atmosphere like?

Answer 2

• formed by volcanic activity
• consisted of mainly carbon dioxide. Perhaps also nitrogen, water vapour and traces of methane and ammonia

Question 3

How did the earths atmosphere evolve?

Answer 3

-photosynthesis by algae and plants decreased the % of carbon dioxide
- the formation of sedimentary rocks and fossil fuels also removed carbon dioxide
- any ammonia and methane was removed by reactions with oxygen

Question 4

What are consequences of rising greenhouse gases?

Answer 4

• rising sea levels
• increasingly common extreme weather events
• changes in temp + amount, timing and distribution of rainfall
• changes to the distribution of wildlife species

Question 5

How does the greenhouse effect cause temperature rise?

Answer 5

• the earth is heated by the sun
• greenhouse gases absorb infrared radiation
• the radiation simulates the bonds in the gas molecules to vibrate, bend and stretch more vigorously, raising their temperature.
• some energy radiated from the earths surface gets trapped in the atmosphere and the temperature rises