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- How people rely on natural systems
How people rely on natural systems
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Clean water, fertile soil and a stable climate come from natural systems working well. When we damage them, we pay the price.
The carbon cycle
Flows include photosynthesis (plants take in carbon dioxide), respiration and decomposition (release it), and combustion (burning releases it).
Burning fossil fuels moves carbon from rocks into the air much faster than natural processes take it back.
Ecosystem services
Pollination: bees and other insects pollinate many food crops.
Clean water: soils and wetlands filter water.
Flood control: forests, wetlands and floodplains store water.
Carbon storage: forests, oceans and peat bogs store carbon.
Food, timber and medicines.
When systems fail
If peat bogs dry out or are dug up, they release stored carbon.
If insect numbers fall, crops may be pollinated less.
Protecting natural systems, for example by restoring wetlands or peat bogs, helps both people and wildlife.
Explain how restoring a peat bog helps people.
- Peat bogs store large amounts of carbon; restoring them stops it escaping as carbon dioxide.
- Wet peat soaks up rainfall and releases it slowly, reducing flooding downstream.
- They also filter water and give habitats for wildlife.
Answer: It locks up carbon, reduces flooding and improves water quality.
Carbon stores: atmosphere, oceans, plants and soils, rocks. Flows: photosynthesis, respiration, decomposition, combustion. Ecosystem services: pollination, clean water, flood control, carbon storage, food and materials. Damaging natural systems can cause floods, carbon release and lower crop yields.
The interactive lesson includes the diagrams for this topic.
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