Topic 8 - The Greenhouse Effect

Question 1

what is the temperature of the earth a balance between?

Answer 1

the energy it gets from the sun and the energy it radiates back into space

Question 2

what is the greenhouse effect?

Answer 2

gases in the atmosphere absorbing heat which would normally be radiated out into space and re-radiating it in all directions (including back towards Earth)

Question 3

what gases in the atmosphere radiate energy back to Earth?

Answer 3

‘greenhouse gases’, water vapour, carbon dioxide and methane

Question 4

why is the greenhouse effect becoming enhanced?

Answer 4

human beings are increasing the amount of carbon dioxide in the atmosphere, and increasing the levels of other gases that can act as greenhouse gases

Question 5

what does the greenhouse effect becoming enhanced cause?

Answer 5

global warming

Question 6

how are carbon dioxide levels increased?

Answer 6

humans release carbon dioxide all the time in everyday lives (e.g. car exhausts and burning fossil fuels)
deforestation increases carbon dioxide levels

Question 7

how are methane levels increased?

Answer 7

methane gas is produced naturally from various sources
rice-growing and cattle rearing also increase methane levels

Question 8

how are nitrous oxide levels increased?

Answer 8

nitrous oxide is released naturally by bacteria in soils and the ocean
more is released from soils after fertiliser is used
it’s also released from vehicle engines

Question 9

how are CFC levels increased?

Answer 9

CFCs were once used in aerosol sprays and fridges. most countries don’t produce them anymore, but some still remain and get released