EQ1.2

Question 1

Explain the significance of carbon sequestration (6 marks)

Answer 1

• Carbon sequestration is the process of carbon being stored for a prolonged period of time in a carbon store, examples of these include oceans, plants and rocks.
• If these were to stop acting as carbon stores it would result in carbon dioxide still being present in the atmosphere which would lead to the ozone layer thickening and preventing even less sun rays to escape back into space. This causes the earth to act as a greenhouse causing the core temperature to increase resulting in weather patterns such as El nino and la nina. La nina is when a warm mass of water is pushed even further west than normal causing droughts in California and el nino causes a reduction in precipitation rates in the Pacific causing droughts again.
• This results in an increase in the number of wildfires which releases more carbon dioxide back into the atmosphere worsening climate change even further. In addition, the increased temperature results in an increase in evaporation rates which reduces the amount of water available to use in hydroelectric power which causes countries to refer back to the more reliable source of fossil fuels which again release more carbon dioxide back into the atmosphere worsening climate change even further. In addition, the increased temperature results in an increase in evaporation rates which reduces the amount of water available to use in hydroelectric power which causes countries to refer back to the more reliable source of fossil fuels which again release more carbon dioxide back into the atmosphere. This shows the significance of carbon sequestration as otherwise there would be an increase in the amount of carbon in the atmosphere which worsens climate change further.

Question 2

Explain the role of the ocean in the carbon cycle (6/8marks)

Answer 2

The ocean stores 38,000 gigantones of carbon, making it one of earth’s most significant carbon stores

Biological pump:

Carbon is stored in organic matter such as algae, plants and coral and is dissolved in water as CO2. This pump sequesters carbon from the atmosphere through the growth of phytoplankton
Carbon is kept in the ocean and passed along the ocean food web. It is then returned to the atmosphere through biological decay
This pump operates on a scale of hours to years and the flux between the ocean and the atmosphere is 11 gigantones a year
Carbonate pump:
-The Carbon pump occurs when dead organic material sinks to the ocean floor and sediments to eventually become carbonate rock like limestone
Physical pump:
-The physical pump in the form of ocean currents and the thermocline cycle moves carbon vertically and horizontally in the ocean

Question 3

Explain the significance in soil in the carbon cycle (6/8marks)

Answer 3

-20 to 30% of global carbon is stored in the soil. 2x the amount in the atmosphere and 3x the amount in terrestrial stores
-Carbon cycling occurs in the soil: decomposition and new plant growth
-Carbon can stay in the soil for decades and centuries if: the carbon is in dead organisms, the soil is clay, or the soil is covered by mangroves
-Soils in cold regions can store 800 tonnes of carbon per hectare. This is especially the case in permafrost soils