Currently there is more carbon dioxide being released into the atmosphere than is being removed. This is mainly due to human activities such as burning fossil fuels and cutting down and burning rainforests. These activities disturb the natural carbon cycle. They result in an increase in the amount of carbon dioxide in the atmosphere. Many scientists believe that rising levels of carbon dioxide in the atmosphere is a major factor
in global warming and climate change. Science in Society
Before the Industrial Revolution, carbon dioxide (CO2 ) was absorbed from the air by land
plants, moved by rivers to the ocean and released back into the air, creating a balanced cycle for centuries. Today humans are changing this balance as large amounts of CO2 we burn fossil fuels like coal, oil and natural gas. About one third of this CO2 by the ocean, changing the ocean from a net provider of CO2
of CO2, i.e. a carbon sink.
1. Investigate the effect that increased levels of carbon dioxide in the oceans has on marine organisms.
2. Research the rate at which the Amazon rainforest is being cut down and how this affects the carbon dioxide levels in the atmosphere.
3. Research the reasons why carbon dioxide levels in the atmosphere have increased since the beginning of the Industrial Revolution.
are released when is absorbed
to the air to a net absorber
Fig. 9 An unbalanced carbon cycle.
Nature of Science
In this chapter we learned about the cycling of water and carbon on Earth. Scientists such as those who work in the Mauna Loa observatory in Hawaii research the amount of carbon dioxide in the atmosphere and generate data relating to it. This data is analysed by scientists to identify patterns and relationships. Question: Do you think it is important for scientists to gather and analyse data about the amount of carbon dioxide in the atmosphere? Explain your answer.
