Atmosphere and climate change - SC21

Question 1

What is the percentage of C02 in the Earth’s atmosphere today?

Answer 1

less than 0.5%

Question 2

CO2 percentage in the atmosphere today is less than the early atmosphere - what caused this decrease?

Answer 2

Carbon dioxide dissolved in oceans and converted into 02 by vegetation

Question 3

How do greenhouse gases in atmosphere keep earth warm?

Answer 3

contribute to greenhouse effect - the earths atmopshere traps heat given from gases to maintain a warm temperature

Question 4

Name 2 processes caused changes in atmosphere composition from earliest to now?

Answer 4

Cooling of atmosphere and photosynthesis

Question 5

how has cooling changed composition of earth’s atmosphere?

Answer 5

water vapour condensed - less H20 in air

Question 6

how has photosynthesis changed composition of Earth’s atmosphere?

Answer 6

plants use C02 to produce 02 and hence earths composition increases in 02 and decreases in C02