The Carbon Budget

Question 1

Where is the vast majority of carbon stored?

Answer 1

In the Earth’s crust and secondly in the oceans.

Question 2

Relatively low amounts of carbon are stored in plants and the atmosphere. Why?

Answer 2

Because these carbon stores are extremely active, with carbon flowing back and forth between the atmosphere and the land.

Question 3

In a tree, what is largely responsible for the net loss of carbon in the atmosphere?

Answer 3

Photosynthesis

Question 4

What shows the importance of trees as carbon sinks?

Answer 4

Photosynthesis

Question 5

What is the greenhouse effect?

Answer 5

Carbon dioxide and other gases eg methane are released into the atmosphere. These gases absorb long-wave radiation from the Earth and warm the lower atmosphere, enabling life to exist on Earth.

Question 6

What is the enhanced greenhouse effect?

Answer 6

In recent decades, increased emissions resulting from anthropogenic activities (eg burning fossil fuels and deforestation) have increased the concentration of greenhouse gases, making them more effective at trapping radiation given off by Earth.

Question 7

What are the impacts of the carbon cycle on the land?

Answer 7

• carbon stored in grass provides fodder for animals.
• carbon provides a valuable source of energy in the form of wood and fossil fuels
• the carbon cycle is responsible for the formation and development of soil. Carbon in the form of organic matter (litterfall) introduces important nutrients and provides important structure to the leaves
• carbon in the form of organic matter is essential for plant growth and the production of food

Question 8

What are the impacts of the carbon cycle on the oceans?

Answer 8

• carbon can be converted into calcium carbonate, which can be used by some marine organisms to build their shells
• the carbon cycle has an impact on the presence and proliferation of phytoplankton (a basic food source for many marine organisms). Phytoplankton consumes carbon dioxide during photosynthesis, and this carbon is then passed along the food chain.

Question 9

What are the impacts of the carbon cycle on the atmosphere?

Answer 9

• carbon dioxide in the atmosphere helps to warm the Earth through the greenhouse effect. Without this, there would be no life on Earth.
• increases in carbon emissions as a result of human activities has led to the ENHANCED greenhouse effect, which threatens to have a profound impact on the Earth’s climate.
• carbon stored in vegetation has a significant impact on the atmosphere, whether deforestation (carbon source) or afforestation (carbon sink).

Question 10

The carbon cycle can have significant regional impacts on climate. For example,

Answer 10

• regions experiencing widespread deforestation may become drier and less humid, and fewer trees means less photosynthesis.
• the proliferation of phytoplankton in the oceans may promote the formation of clouds, through the creation of the chemical substance DMS.
• volcanic eruptions release carbon dioxide into the atmosphere along with ash and other gases. This absorbs more incoming radiation from the sun and can lead to a cooling effect on Earth “volcanic winter”.
• vegetation removes carbon dioxide from the atmosphere, and releases water an oxygen. Regions with dense vegetation (ie tropical rainforests) experience high rates of photosynthesis and respiration. This increases levels of humidity and the amount of cloud cover, which in turn may affect regional temperatures and rainfall.