Natural Cycles: Carbon and Nitrogen

What is Natural Cycles: Carbon and Nitrogen?

Within Earth & Environmental Science, which covers our planet, its resources and ecosystems, and how people can protect the environment, this topic explains Natural Cycles: Carbon and Nitrogen. Earth and environment topics show how the planet’s systems shape landscapes, climate and life, with models that make these processes visible.

Check that you can explain Natural Cycles: Carbon and Nitrogen in your own words and give one example from everyday life. If you can do that, you have understood the core idea.

Understanding Natural Cycles: Carbon and Nitrogen helps you explain the environment around you and weigh up how people can protect it.

Natural Cycles: Carbon and Nitrogen in detail

Carbon moves between the atmosphere, oceans, living things, soil and rocks. Plants take in carbon dioxide by photosynthesis, animals eat plants, and carbon returns through respiration, decomposition and combustion. Long-term stores include fossil fuels and limestone, and oceans absorb a lot of carbon dioxide. Human burning of fossil fuels adds carbon faster than natural sinks can remove it.

Nitrogen makes up 78% of air but is unusable by most organisms until nitrogen-fixing bacteria (in soil and legume root nodules) and lightning convert it into nitrates. Plants absorb nitrates, animals eat plants, decomposers return ammonia, nitrifying bacteria convert it to nitrates and denitrifying bacteria return nitrogen to the air. Fertilisers and fossil fuels have changed the nitrogen cycle, causing pollution.

How the interactive helps you understand Natural Cycles: Carbon and Nitrogen

Watch the cycle in the interactive. Use any sliders or buttons it offers to change the values and see how the cycle responds.

Before you change anything, predict the result. Then change one value at a time and check whether your prediction was right. This is a quick way to build a correct mental model of Natural Cycles: Carbon and Nitrogen.

Real-life uses and examples

• Explain how Natural Cycles: Carbon and Nitrogen affects the landscape or climate near you.
• Link Natural Cycles: Carbon and Nitrogen to a real environmental problem and a possible solution.
• Use a diagram of Natural Cycles: Carbon and Nitrogen to describe the steps of a process in order.

Common mistakes to avoid

• Describing a process without the timescale it works over.
• Presenting one cause as the only cause of an environmental change.
• Learning the definition without testing it. Use the quiz and the interactive to check that you can apply the idea.