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B. People and Environments: Canada's Interactions with the Global Community · Canada's Interactions with the Global Community

Environmental Issues Don't Stop at Borders

B1.3 B1.1About 45 minutes
Learning goals
  • I can explain why some environmental issues are of international importance.
  • I can explain why solving them needs the participation of Canada and other regions.
  • I can describe accords Canada has joined to protect the shared environment.
  • I can describe actions I can take to help.

Words to know

shared resource
A natural resource that more than one country uses, like the Great Lakes, the oceans or the air.
migratory species
Animals that travel long distances between places, often across borders, like many birds, whales and butterflies.
greenhouse gases
Gases, such as carbon dioxide, that trap heat in Earth's atmosphere. More of them causes climate change.
ozone layer
A layer of gas high above Earth that blocks much of the sun's harmful ultraviolet (UV) rays.
acid rain
Rain made acidic by air pollution; it can harm lakes, fish and forests.
cooperation
Working together toward a shared goal.

Smoke without a passport

In the summer of 2023, smoke from wildfires in Canada drifted south and turned skies hazy in cities in the United States, such as New York. Smoke doesn't stop at a border to show its passport!

Nature does not follow the lines on a map. That is why many environmental issues are international.

A city skyline under a hazy orange sky, with the Sun a dim red disc through smoke.
Wildfire smoke can drift hundreds of kilometres and cross borders. Air pollution is an environmental issue that no country can solve alone. AI-generated image

Why some environmental issues are international

  1. Air moves. Wind carries smoke, pollution and acid rain from one country to another.
  2. Water moves. Rivers flow across borders. The Great Lakes are shared by Canada and the United States. Ocean currents carry plastic around the world.
  3. Animals move. Migratory species like Canada geese, monarch butterflies and whales travel between countries. Protecting them in one country is not enough.
  4. The atmosphere is shared. Greenhouse gases from every country mix in the air and add to climate change, which affects everyone.
  5. Resources are shared. Fish in the ocean belong to no single country. If every country overfishes, the fish disappear for everyone.
Country ACountry Bfactorywindpolluted air arrives
Pollution from a factory in one country can be carried by the wind across the border. Country B can't fix this alone.

Why everyone must take part

Imagine Country B works hard to clean its air, but Country A next door keeps polluting. Country B's air will still be dirty. For shared problems, every country that adds to the problem must help solve it.

Canada is part of the problem and part of the solution: Canadians use energy, make waste and buy products from around the world. Canada also has huge forests, the Arctic, long coastlines and lots of fresh water to protect.

AccordYearProblem it tackles
Migratory Birds Convention (Canada and the United States; signed by Britain for Canada)1916Protecting birds that fly between the two countries
Great Lakes Water Quality Agreement (Canada and the United States)1972Cleaning up and protecting the shared Great Lakes
Montreal Protocol1987Chemicals damaging the ozone layer
Canada–United States Air Quality Agreement1991Air pollution, including acid rain
Paris Agreement2015Greenhouse gases and climate change
Some environmental accords Canada has joined.

A success story

After the Montreal Protocol, the world phased out most chemicals that damage the ozone layer. A UN-backed scientific assessment in 2023 reported that the ozone layer is on track to recover over the coming decades. It shows what countries can do when they all take part.

Worked example

Let's explain why one country can't do it alone

Monarch butterflies travel between Canada, the United States and Mexico. Ontario plants milkweed to help them. Why isn't that enough?

  1. Step 1: Follow the journey. Monarchs that spend summer in Canada fly south through the United States to spend the winter in Mexico.
  2. Step 2: Find the needs in each place. They need milkweed and flowers along the way, and safe forests to spend the winter in.
  3. Step 3: Find the weak link. If the winter forests in Mexico or the feeding areas in the United States are lost, the monarchs Ontario helped may still not survive.
  4. Step 4: Conclude. Protecting a migratory species needs all three countries to take part.

Monarchs depend on habitat in three countries. Ontario's milkweed helps, but the species needs cooperation along the whole route.

A monarch's year needs three countriesCanadasummer: milkweedfor caterpillarsUnited Stateson the way: flowersfor foodMexicowinter: safe foreststo rest inspring and summer: new generations fly back northa diagram, not a map
Solid arrows show the trip south in fall; the dashed arrow shows new generations returning north. Monarchs need milkweed in Canada, flowers along the way in the United States and winter forests in Mexico. If any one link breaks, the whole journey fails.
Just for fun

Monarch butterflies fly thousands of kilometres between Canada and Mexico with no passport, no map and no snack bag. Talk about travelling light! 🦋

Hands-on activity

The shared lake

You need: a large clear bowl or baking dish of water, food colouring, and a spoon. A grown-up should handle the food colouring, because it can stain. Do this on a tray or in the sink.

  1. Pretend the bowl is a lake shared by two countries. Lay a spoon or pencil across the middle as the "border".
  2. Put 2 drops of food colouring on one side. This is "pollution" from one country.
  3. Watch for 2 minutes, then gently stir once, like a current. What happens on the other side of the border?
  4. Talk about it: Can the country on the clean side keep its water clean by itself? What would the two countries need to agree on?

What to look for: your child notices the colour spreads across the "border" and explains that both countries must agree to stop polluting. Pour the water down the drain afterwards.

Your turn

1

Give three reasons some environmental issues are international.

2

Which lakes are shared by Canada and the United States, and which agreement protects them?

3

What is a migratory species? Give an example.

4

Why can't one country solve climate change alone?

5

What did the Montreal Protocol do, and did it work?

6

Name one thing you can do to help a shared environmental problem.

More practice: warm-up

1

What carries smoke from one country to another?

2

What does the ozone layer do?

3

What is acid rain?

4

What year was the Paris Agreement made?

5

Name one migratory animal that travels between Canada and Mexico.

More practice: on your own

1

Explain how plastic thrown away in one country can end up on a beach in another.

2

Why did Canada and the United States need an agreement about acid rain?

3

If only some countries stop overfishing, what might happen to fish stocks? Why?

4

Use the wildfire smoke example from 2023 to explain interdependence.

5

Why is the Montreal Protocol called a success?

Challenge

1

Explain why the Montreal Protocol worked well, while reducing greenhouse gases has been harder.

2

Canada has much of the world's fresh water and a large part of the Arctic. Why does this give Canada a special responsibility in international environmental cooperation?

3

Design a short plan for an environmental agreement between two countries that share a polluted river. Include three rules and one way to check if they work.

Check your understanding

Quiz

1.

Why are many environmental issues international?

2.

Which agreement protects the Great Lakes?

3.

The Montreal Protocol protects...

4.

Why can't one country solve climate change alone?

5.

Monarch butterflies need habitat in...

6.

Acid rain is caused by...

For parents and teachers

Big idea: Many environmental issues are international because air, water and animals cross borders and the atmosphere and oceans are shared. Solving them needs every contributing region, including Canada, to take part, as shown by accords like the Great Lakes Water Quality Agreement, the Montreal Protocol and the Paris Agreement.

How to help at home:

  • Do the shared-lake demonstration together (handle food colouring yourself; it stains).
  • Look at an air-quality or wildfire-smoke map online and notice how smoke crosses borders.
  • Choose one family action, such as planting milkweed or reducing single-use plastic.

Common difficulties:

  • Thinking a country can fix shared problems alone. Use the bowl demonstration to show why everyone must take part.
  • Feeling overwhelmed by climate change. Point to the Montreal Protocol as proof that cooperation can work, and focus on actions.