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Everything on the GCSE Biology Human Impact on Ecosystems poster is written out below, section by section. Use it to search the sheet, copy parts into your own notes, or check a fact quickly.
Human Activities & Environmental Change
Human activities can damage ecosystems, but conservation measures can protect and restore them.
Human activities
- Burning fossil fuels (coal, oil and gas).
- Deforestation – cutting down large areas of forest.
- Pollution – waste, chemicals and plastics entering the environment.
- Overfishing – removing fish faster than populations can recover.
Environmental changes
- Air pollution – harmful gases released into the atmosphere.
- Water pollution – chemicals and sewage entering rivers and lakes.
- Land pollution – rubbish and toxic chemicals contaminating soil.
- Global warming – greenhouse gases trap extra heat in the atmosphere.
Consequences
- Habitat loss – homes for plants and animals are destroyed.
- Reduced biodiversity – fewer species in an area.
- Extinction – species may die out completely.
- Rising sea levels – as ice melts and oceans expand.
- Food shortages – less food available for people and wildlife.
Global Warming
Greenhouse gases such as CO₂, CH₄ and N₂O trap heat in the atmosphere. More of these gases means more heat is retained, so the Earth's average temperature rises.
Effects include:
- Ice melting at the poles and in glaciers.
- Rising sea levels.
- More extreme weather, such as droughts, floods and storms.
Types of Pollution
Air pollution
- Caused by burning fuels in cars, factories and power stations.
- Contributes to climate change and acid rain, and can cause breathing problems.
Water pollution
- Sewage, fertilisers and industrial chemicals enter rivers and lakes.
- Can cause eutrophication – excess nutrients trigger algal blooms that use up oxygen and kill aquatic life.
Land pollution
- Rubbish, plastics and toxic chemicals contaminate soil.
- Damages habitats and can harm plants and animals directly.
Conservation Methods
Protect
- Nature reserves and protected areas.
- Laws to protect species and habitats.
- Bans on hunting or trading endangered species.
Restore
- Reforestation – planting trees to replace those lost.
- Habitat restoration.
- Captive breeding programmes for endangered species.
Reduce
- Recycling and reducing waste.
- Using renewable energy instead of fossil fuels.
- Sustainable fishing and farming.
- Cutting greenhouse gas emissions.
Biodiversity
Biodiversity is the variety of living organisms in an ecosystem. High biodiversity helps keep ecosystems stable and healthy. Human activities that cause pollution and climate change reduce biodiversity and can lead to extinction.