How do human activities affect the environment, and what can we do to help?
Describe how human activities cause pollution and harm the environment, and explain ways people can reduce their impact
A practical answer to the N(T) Science point on human impact. The main types of pollution, how human activity harms the environment, and practical ways people can reduce their impact.
Reviewed by: AI editorial process; not yet individually human-reviewed
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What this dot point is asking
This dot point wants you to describe how human activities harm the environment, mainly through pollution, and to explain what people can do to reduce their impact. The big idea is that the way humans live, by burning fuels, making waste and using land, can damage the air, water and land that all living things depend on. But people can also make choices, like reducing waste and saving resources, that protect the environment.
The answer
How humans affect the environment
Humans depend on the environment for clean air, clean water, food and resources. But many human activities damage it. The most common way is pollution, which is adding harmful substances to the air, water or land. Human activity also clears land and uses up resources, which affects the plants and animals that live there.
Types of pollution
There are three main types of pollution to know:
- Air pollution: harmful gases and smoke released into the air, mostly from burning fuels in factories, power stations and vehicles. It can harm people's breathing and add to global warming.
- Water pollution: harmful substances released into rivers, lakes and the sea, such as waste chemicals, sewage or oil. It can poison or kill the fish and other living things in the water and make it unsafe to use.
- Land pollution: rubbish and waste dumped on the land, such as plastic and other litter, much of which does not rot away and can harm animals and spoil the land.
Other harm from human activity
Besides pollution, humans harm the environment in other ways:
- Cutting down forests removes the homes (habitats) of many plants and animals and reduces the trees that take in carbon dioxide and give out oxygen.
- Using up resources such as fossil fuels, which are non-renewable and will run out, and which pollute when burned.
- Dropping litter and plastic, which can harm wildlife, for example animals trapped in or eating plastic.
These harms can reduce the number and variety of living things in a place.
How people can reduce their impact
The good news is that people can make choices that protect the environment. A useful rule is reduce, reuse and recycle:
- Reduce: use less in the first place, for example less electricity, less water and less plastic.
- Reuse: use things again instead of throwing them away, such as refilling a water bottle or using a cloth bag.
- Recycle: collect used materials like paper, glass, plastic and metal so they can be made into new things, instead of going to waste.
Other helpful actions include saving electricity and water, walking or cycling instead of driving, planting trees, and not dropping litter. Factories can also treat their waste before releasing it and fit filters to trap smoke.
Why it matters
Looking after the environment keeps the air and water clean, protects the homes of plants and animals, and saves resources for the future. Because all living things are linked, damage to the environment can affect food chains, water supplies and people's health. Caring for the environment is caring for ourselves.
Examples in context
Example 1. Plastic in the sea. Plastic bags and bottles dropped as litter can be washed into rivers and out to sea, where they harm sea animals that get trapped in them or swallow them. Because plastic does not rot away, it stays for a very long time. This is why cutting down on single-use plastic and recycling it matters so much.
Example 2. Cycling instead of driving. When people walk or cycle for short trips instead of driving, fewer vehicles burn fuel, so less air pollution and less carbon dioxide are released. It also saves the fuel itself. A simple everyday choice like this reduces a person's impact on the environment.
Try this
Cue. Name the three main types of pollution. The three main types are air pollution, water pollution and land pollution.
Cue. Explain how recycling helps the environment. Recycling means less waste goes to landfill and fewer new raw materials are taken from the Earth, which saves resources and reduces pollution from making new things.
Cue. Give two everyday actions a person could take to reduce their impact on the environment. For example: save electricity by switching off lights and appliances, and use less plastic by reusing a refillable bottle. (Accept other sensible actions.)
Exam-style practice questions
Practice questions written in the style of SEAB exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
Original4 marksA factory pours waste chemicals into a river and pumps smoke into the air. (a) Name the type of pollution caused in the river. (b) Name the type of pollution caused in the air. (c) State one harm the river pollution could cause. (d) Suggest one thing the factory could do to reduce its pollution.Show worked answer →
(a) The waste chemicals in the river cause water pollution.
(b) The smoke pumped into the air causes air pollution.
(c) Any sensible harm, for example: the chemicals could poison or kill the fish and other living things in the river, or make the water unsafe for animals and people to use.
(d) Any sensible action, for example: clean (treat) the waste before releasing it, fit filters to the chimney to trap the smoke, or stop releasing the chemicals into the river.
What markers reward: naming water pollution and air pollution correctly, one real harm such as killing river life, and one genuine way to reduce pollution (treating waste or fitting filters).
Original3 marksPeople are encouraged to 'reduce, reuse and recycle'. (a) State what 'recycle' means. (b) Explain how recycling helps the environment. (c) Give one other everyday action that helps protect the environment.Show worked answer →
(a) Recycle means to collect used materials (such as paper, glass, plastic and metal) and process them so they can be made into new things instead of being thrown away.
(b) Recycling helps the environment because it means less waste goes to landfill, and fewer new raw materials need to be taken from the Earth, which saves resources and reduces pollution from making new materials.
(c) Any sensible action, for example: save electricity and water, use less plastic, walk or cycle instead of driving, or plant trees.
What markers reward: a clear meaning of recycle, explaining that it cuts waste and saves raw materials, and one more genuine environment-protecting action.
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