B. Natural Resources Around the World: Use and Sustainability · Natural Resources Around the World: Use and Sustainability

Effects of Resource Extraction and Use on People and the Environment

B3.3About 50 minutes

Learning goals

I can identify short-term and long-term effects of resource extraction and use.
I can explain environmental effects like deforestation, desertification, smog, acid rain, climate change, soil contamination, habitat destruction and flooding.
I can describe both positive and negative effects on people.

Words to know

short-term effect
An effect that happens quickly or lasts a short time, like noise from blasting or a muddy stream.

long-term effect
An effect that lasts for years or generations, like a lost forest or a changed climate.

desertification
When dry land becomes more like a desert, often because of overgrazing, cutting trees or overusing water.

smog
Harmful haze of air pollution, often from burning fuels, that can make breathing difficult.

acid rain
Rain or snow made acidic by pollution (mainly sulphur dioxide and nitrogen oxides) from burning fuels and smelting ore.

tailings
Finely ground rock and water left over after the valuable metal is removed from ore.

habitat destruction
Damaging or removing the natural home of plants and animals.

Remember from Grade 6

In Grade 6 science you looked at short-term and long-term impacts of making electricity, and in Grade 6 social studies you saw how acid rain and climate change cross borders. Now you'll look at all kinds of resource extraction and use, around the world.

Hook: the story of Sudbury

For much of the 1900s, smelters near Sudbury, Ontario, roasted nickel and copper ore. The smoke was full of sulphur dioxide. It caused acid rain, killed plants, and left hills of bare, blackened rock. Lakes became too acidic for many fish.

Then things changed. Companies cut their emissions a lot, and starting in 1978 the city's Regreening Program spread crushed limestone on the acidic soil and planted millions of trees. Today, many of those hills are green again and many lakes are recovering.

The story shows two things: resource use can have serious long-term effects, and people can repair some of the damage.

Young pine and birch trees grow among dark, blackened bedrock on a hillside above a blue lake. — The dark rock shows the damage from decades of smelter pollution; the young trees show the regreening. Many hills near Sudbury look like this as they recover. AI-generated image

Sudbury's story in four steps: smelter smoke, acid rain damage, the Regreening Program from 1978, and green hills today.

Effect	Common causes	Short-term or long-term?
Deforestation	Clearing forests for farms, roads, mines	Long-term (forest and habitat lost for decades or more)
Desertification	Overgrazing, cutting trees, overusing water in dry lands	Long-term
Smog	Burning fossil fuels in vehicles, factories, power plants	Short-term episodes (a smoggy day), with long-term health effects
Acid rain	Sulphur dioxide and nitrogen oxides from smelters and burning coal	Long-term damage to lakes, soil and forests
Climate change	Greenhouse gases from burning fossil fuels and cutting forests	Long-term (lasting many generations)
Soil contamination	Mine tailings, oil spills, too many chemicals	Long-term
Habitat destruction	Mining, logging, dams, roads, bottom trawling	Short- and long-term
Flooding	Dams creating reservoirs; cutting forests (faster runoff)	Long-term for reservoirs; short-term floods after heavy rain

Some effects of resource extraction and use.

A closer look at some effects

Desertification: The Aral Sea in Central Asia was once one of the largest lakes in the world. Starting in the 1960s, rivers feeding it were used to irrigate cotton fields. The lake shrank to a small part of its size, leaving behind dry, salty, dusty land. Fishing towns were left far from the water, and dust storms harm people's health.
Soil and water contamination: Mine tailings are stored behind dams. In 2014, the tailings dam at the Mount Polley mine in British Columbia failed and released mine waste into nearby lakes and creeks.
Flooding: A hydroelectric dam creates a reservoir that floods forests, wetlands and sometimes communities. As flooded plants rot, mercury that occurs naturally in soil can change into a form that builds up in fish. This has been a serious concern for some First Nations and Inuit communities who rely on fish from rivers and lakes changed by dams.
Habitat destruction: Clearing forests or dragging nets on the sea floor removes the homes of plants and animals.

Effects on people

Resource use also has positive effects: jobs, income, taxes that pay for schools and hospitals, energy and products people need. But it can harm health (polluted air or water), destroy traditional food sources, and force people to move. When the resource runs out or prices drop, a whole resource town can lose its jobs (a "boom and bust").

Worked example

Let's sort effects: a new open-pit mine

A new open-pit gold mine opens near a lake. Sort these effects into short-term and long-term, and positive or negative: dust and noise from blasting; 400 new jobs; a large pit and piles of waste rock; tailings stored for many years; a new road to the area.

Dust and noise from blasting: short-term (while the mine runs), negative.
400 new jobs: short- to medium-term (lasting while the mine operates), positive.
A large pit and waste rock piles: long-term, negative (changes the land for a very long time unless reclaimed).
Tailings stored for many years: long-term, negative risk (could leak into the lake).
A new road: long-term; both: better access for people, but it can also bring more hunting pressure, traffic and habitat break-up.

Short-term: dust/noise (−), jobs (+, while the mine lasts). Long-term: pit and waste rock (−), tailings (−), road (+ and −). Most effects on the environment last longer than the jobs.

The new open-pit mine's effects sorted by time (short or long) and by positive or negative. The road lands in two boxes.

Just for fun

Funny but true: Sudbury's regreeners spread crushed limestone on acidic soil. Limestone neutralizes acid, so the hills basically got a giant antacid!

Hands-on activity

Erosion experiment: why trees matter

You need: two baking trays or shallow plastic containers, soil, a small piece of sod (grass with roots) or a layer of moss or leaves, a watering can or cup, and two bowls. Do this outside or in a sink. (Ask a grown-up first.)

Fill both trays with soil. On one tray, lay the sod or plant cover on top. Leave the other tray bare.
Tilt both trays slightly with a book under one end. Put a bowl at the low end of each.
Slowly pour the same amount of water onto the top of each tray, like rain.
Compare the water in the two bowls. Which is muddier? Which tray lost more soil?

Expected result: the bare tray loses much more soil and its water is muddier. Plant roots hold soil in place. This is why clearing forests can cause soil erosion and muddy rivers.

Wash hands after handling soil.

Your turn

What causes acid rain?

Give one short-term effect and one long-term effect of a forest being clear-cut.

What happened to the Aral Sea, and why?

What are tailings?

How can a hydroelectric reservoir affect fish that people eat?

Name two positive effects of resource extraction on people.

What did Sudbury's Regreening Program do?

More practice: warm-up

Is a smoggy day a short-term or long-term effect?

What is deforestation?

Which gas from Sudbury's smelters caused acid rain?

What do greenhouse gases contribute to?

What is habitat destruction?

More practice: on your own

Explain why cutting forests can lead to flooding.

Why might the jobs from a mine be called a short- or medium-term effect but the pit a long-term effect?

What is a resource town "boom and bust"?

How is desertification an effect on people as well as land?

Why is the Sudbury story hopeful?

Challenge

Climate change is called a long-term effect of fossil fuel use. Explain why its effects last so long.

Explain how one resource activity can cause three different effects from the list (deforestation, smog, acid rain, climate change, soil contamination, habitat destruction, flooding).

A government must choose between a dam that floods 100 km² of forest and a natural-gas power plant. Compare their main long-term effects.

Check your understanding

Quiz

Which is the main cause of acid rain?

Why did the Aral Sea shrink?

Which is a long-term effect?

What are mine tailings?

How can cutting down forests increase flooding?

Which is a positive effect of resource extraction on people?

What did Sudbury do to help its land recover?

For parents and teachers

How to help: When you see a news story about pollution, a mine, a dam or a forest fire, ask "Short-term or long-term? Who is affected?" Encourage your child to name both benefits and harms.

Safety: In the erosion experiment, work outdoors or in a sink, and wash hands after handling soil.

Common difficulties:

Mixing up short-term (quick or brief) with small. A short-term effect can be serious.
Listing only harms. Resource extraction also brings jobs and products people need; the goal is to weigh both.
Confusing smog (air pollution near the ground) with climate change (long-term warming). Both can come from burning fossil fuels, but they are different effects.