Climate Change - Physical and Human Causes

Question 1

Name the 4 physical causes of climate change.

Answer 1

Physical: sunspots, volcanic eruptions, ocean currents and Milankovitch cycles.

Question 2

Name the 4 human causes of climate change.

Answer 2

Increased methane, burning of fossil fuels, deforestation, CFCs.

Question 3

Physical 1/4

Tell me about sunspots.

Answer 3

an increase in sunspot activity will increase global temperatures.
Sunspot activity follows 11 and 22 year cycles.
The little ice age of 1450 to 1700 may be due to low sunspot activity.

Question 4

Physical 2/4

Tell me about volcanic eruptions.

Answer 4

When volcanoes erupt they throw millions of tonnes of ash, dust and sulfur dioxide into the atmosphere.
This produces aerosols that can reduce the amount of sunlight reaching earth, leading to temporarily cooler temperatures.
Major eruptions have been linked to global cooling, for example Mt St Helens (1980)

Question 5

Physical 3/4

Tell me about the ocean currents.

Answer 5

changes in the size and direction of ocean currents can change the distribution of energy around the globe.
Some currents flow towards the tropics, transporting cold water from the poles, and others flow towards the poles, transporting warm water from the tropics.
Examples include El Nina which causes cooling, and El Nino which causes warming of areas in the Pacific Ocean.
(‘a’ comes before ‘o’ and cold comes before hot)

Question 6

Physical 4/4

What are the Milankovitch cycles?

Answer 6

they are variations in the earth’s orbit - specifically stretch, tilt and wobble of the globe.
They are linked to long term variations in the earth’s climate, since they affect the amount of energy received from the sun in different regions

Question 7

Human 1/4

Tell me about the burning of fossil fuels.

Answer 7

fossil fuels such as coal, oil and natural gas release CO2 into the atmosphere when they are burned.
Coal has been used extensively in power stations to generate electricity used to heat homes
Increased car ownership has resulted in more petrol and diesel being burned, which means more CO2/nitrus oxide is being released into the atmosphere as it is in car exhaust.

Question 8

Human 2/4

Tell me about increased methane.

Answer 8

The increase in global population has lead to an increase in food demand. More methane is being released from rice plants in padi fields as rice production is increasing to meet demands. The increase in demand for beef has resulted in an increase in methane being released into the atmosphere as it is in cow belches and dung.
Methane is more than 20 times as effective than CO2 at trapping heat.
Methane accounts for 20% of the enhanced greenhouse effect, and it remains in the atmosphere for 12 years

Question 9

Human 3/4

What’s the deal with CFCs?

Answer 9

CFCs are more than 10,000 times as effective than CO2 at trapping heat in the atmosphere. CFCs are released if the insulation in old refrigerators is disposed of incorrectly.

Question 10

Human 4/4

Tell me about deforestation.

Answer 10

Deforestation decreases the amount of CO2 being absorbed from the atmosphere, since there are less trees. If the wood is burned, it will release CO2