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Earth Month: Climate Change

Flood water with traffic sign submerged.

Flooding in Davenport, Iowa (Kelly Sikkema, Unsplash)

Flood water with traffic sign submerged.

Flooding in Davenport, Iowa (Kelly Sikkema, Unsplash)


How does this align with my curriculum?

Discover the probable causes, likely effects, and potential ways to mitigate climate change.

Climate Change

In March of 2022, the North and the South Pole were hotter than normal. How much hotter? Quite a bit as it turns out. Researchers in Antarctica saw temperatures that were more than 40 degrees Celsius higher than normal. Stations near the North Pole featured similar readings. They were approximately 30 degrees Celsius higher than normal.

Image of shrinking Arctic sea ice from NASA
The shrinking extent of Arctic sea ice (NASA Goddard Space Flight Center, Flickr)
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Shown is a colour illustration of ice around the north pole of Earth.

The Earth is set against black space. Water is shown in dark greenish blue, land in beige, and ice in grey and white. Faint grey lines of longitude and latitude are visible on the globe. The lines of longitude meet in the centre of the illustration. There is an irregular shaped patch of ice around this point. This ice is in the arctic ocean. It stretches almost to the northern edge of Greenland, Ellesmere Island and close to other arctic archipelagos in Canada, Norway and Russia.

There are several reasons for these higher-than-normal temperatures. One reason is the ‘atmospheric rivers’ that brought hot, moist air to the poles. It was unusual, but it only lasted for a short amount of time. The other reason is increasing average polar temperatures. Temperatures in these regions have gone up by a full degree Celsius in the past decade.

It is important to keep both of these reasons in mind as they illustrate an important difference. This is the difference between weather and climate.

Weather is what happens outside your window at any given moment. It can change quite quickly. One moment it could be sunny and warm, and then next a storm system could move in and change the weather to rainy and cold.

Climate refers to the usual weather in a place over a long period of time. Climate changes very slowly, especially compared to the weather.

Scientists across the globe agree that climate is now changing faster than anytime in modern human history.

Illustration of the differences between weather and climate
The difference between weather and climate (©2021 Let’s Talk Science)
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Shown is a colour, comic-style illustration of a set of clothes for one day, labelled weather, and a closet full of clothes, labelled climate.

The background is purple background shaded with pink dots. On the top left side of the panel is the caption "weather" in blue. Below, several items of clothing float next to a yellow sun. A baseball cap, sunglasses, tank top, shorts, and sandals. Another caption in blue describes this as "what you wear each day".

On the top right side of the panel is the caption "climate" in yellow. Below is a wardrobe with both doors open. Inside are piles of clothes on a shelf and hanging up. These include sweaters, jeans, t-shirts, scarves, toques and mittens. On the floor of the wardrobe are rubber boots, running shoes, and snow boots. Another caption in yellow describes this as "what you wear over the year".


Carbon: Too Much Of A Good Thing

Carbon, an important chemical element, is one of the key building blocks of life. The bodies of living beings are partly carbon, as is our food. Many of the things we take for granted, such as clothing, are carbon-based as well. Carbon can also be found in rocks, in bodies of water, in soil and the atmosphere.

CO2, or carbon dioxide, is a common form of carbon that we encounter everyday. For example, we breathe in oxygen and breathe out carbon dioxide. Some of this CO2 goes into the atmosphere, and some of it is taken in by plants.

kids running in the forest
Children running in a forest (Source: monkeybusinessimages via iStockphoto).
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Shown is a colour photograph of eight children walking and running along a path in a forest.

Four children run and jump, smiling, along a wide path under tall coniferous trees. The sun shines through the trees making shadows across the path. In the background, four older children walk side-by-side.


But since the middle of the 19th Century, we humans have been steadily increasing the amount of carbon we put into the atmosphere.

Did you know?

A single mature tree can absorb approximately 22 kg (48 lbs) of CO2 in a year.

Modern human history began when human beings settled into agrarian societies. These are groups of people who farmed together.

Crops growing from the soil
Growing crops (Source: Steven Weeks via Unsplash).
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Shown is a colour photograph of green plants growing in two straight rows.

The camera is at ground level. A wide stripe of dark brown soil stretches across most of the bottom edge of the photograph and narrows into the distance. On each side of the soil, a row of green plants with long leaves reaches over the soil in an arch shape.



Beginning in the late 18th Century, human civilizations began to fundamentally change.

Humans developed new kinds of machines. These machines used new kinds of energy, such as the energy from steam. This allowed humans to develop large-scale manufacturing.

This period of time became known as the first Industrial Revolution. During this time, production shifted from agriculture and hand-crafted goods to factories.

Napier & Son Ltd, 'Aero Engine in the Making', England, circa 1918
Napier & Son Ltd, 'Aero Engine in the Making', England, circa 1918 (Source: Museums Victoria via Unsplash).
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Shown is black and white photograph of two people working at large machines in a factory.

In the foreground, one person in a vest and flat cap has their back to the camera. They are turning a small wheel on a metal machine with their left hand. A belt loops around a cylinder on the machine and stretches up and out of the frame. 

In the middle ground, a person black tie and a light coat with dark grime all over the front. They look into the camera.

All around them, the room is filled with dozens of belts stretching up from machines to the ceiling, like a forest.


This Industrial Revolution was powered by fossil fuels. A lot of our electricity generation and transportation still uses these fuels. They are so named because they come from substances that were created in the ground over extremely long time periods. Fossil fuels come from decaying and compressed organic matter, such as plants and animals. When burned, fossil fuels generate greenhouse gases (GHGs).

The Greenhouse Effect

The reason you can exist comfortably and spend time outdoors is because of the atmosphere. The atmosphere keeps the Earth warm. The average temperature on Earth is 15℃. Without the atmosphere to keep things cozy, it would be a bone-chilling -18℃. Very little could survive on such a planet.

The moon is a good example of a planetary body without an atmosphere. Even a planet with a thin atmosphere, such as Mars, is not capable of sustaining life in the same way that the Earth does.

The Moon
The Moon (Gregory H. Rivera, Wikimedia Commons)
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Shown is a black and white photograph of the moon surrounded by black space.

The surface textures of the moon are visible. There is a round, pale shape near the bottom left. Pale streaks extend from it like a sunburst. There are other similar, smaller shapes dotted around the globe. There are also patches of dark area grey, with blurred, uneven edges, mostly near the top and left of the globe.


How does the Earth’s atmosphere do this? Essentially, the Earth acts like a large greenhouse.

Greenhouses are structures humans build to grow plants. Sunlight enters a greenhouse and warms the plants and other surfaces inside. The heat that is generated warms the air inside the greenhouse. The warm air gets trapped by the windows. Our atmosphere traps heat in a similar way.

Earth in a greenhouse
An illustration of the Earth inside of a greenhouse (© 2021 Let’s Talk Science).
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Shown is a colour illustration of planet earth inside a transparent greenhouse.

The whole globe is visible through the transparent panels that make up the walls and peaked roof of the greenhouse. The planet is mostly blue water, with land masses shown in green. Whispy white clouds float just above the surface.


On Earth, sunlight heats up the land and the oceans. The heat that is generated travels up towards space. It is prevented from leaving by gases present in the atmosphere that are good at trapping heat. These are:

  • Carbon Dioxide (CO2)
  • Methane (CH4)
  • Nitrous Oxide (N2O)
  • Hydrofluorocarbons (HFCs)
  • Perfluorocarbons (PFCs)
  • Sulphur Hexaflouride (SF6)
  • Water Vapour

These gases are what people refer to as greenhouse gases. Most of these gases are produced naturally. Others, like hydrofluorocarbons and perfluorocarbons, are only produced by people.

Since the Industrial Revolution, human activity has increasingly put more of these gases into the atmosphere. This has trapped an increasing amount of heat. In turn, this has caused temperatures to rise around the planet. This increase is the driving force behind climate change.

Solar panels in the foreground and wind turbines in the background
Solar panels and wind turbines (Source: zhongguo via iStockphoto).
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Shown is a colour photograph of the sun glinting off solar panels, with wind turbines in the background.

The camera is low, near the surface of the panels. They are rectangular, with silver metal frames, fastened together in a long row, three panels high. They appear dark blue with a grid of thin silver lines. Thinner silver lines are laid across the grid, like pinstripes. 

In the background, the sun is low near the horizon. Gold sunlight is reflected on the solar panels. Three wind turbines, each with three blades, are in silhouette against the sky.

The Warming Earth

The amount of GHGs in the atmosphere has broken records. Big records. In fact, there are more GHGs in the atmosphere now than at any time in the past two million years. This has led to a warmer Earth overall. Scientists estimate that, on average, the Earth is 0.8-1.2C warmer than the beginning of the first Industrial Revolution. 

Did you know?

The amount of carbon dioxide in the atmosphere has increased 46% since the mid-19th Century.

There are a few ways in which scientists have been able to track temperature changes historically.

We have about a century or so worth of temperature data taken directly from thermometers. These are used at weather stations around the world.

Illustration of a thermometer
Illustration of temperature measurements (©2021 Let’s Talk Science).
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Shown is a colour, comic-style illustration of three different thermometers.

In the top left corner is an LCD screen with digital numbers reading 14 degrees celsius. In the centre is a thermometer with red liquid and a scale marked with black lines. The liquid reaches from a bulb on the left end, close to the top of the scale on the right. In the bottom left corner is a round, white thermometer with a dial that goes from -40 degrees to 140 degrees Fahrenheit. A black hand points to 60 the degree mark.

The background is green shaded to blue at the bottom, overlaid with bright pink stripes.


To get temperature data before that, scientists can use the rings in tree cores to estimate past temperature averages. They can also measure the layers in ice core samples taken from glaciers  or ice sheets.

Researchers removing an ice core. Ice core with layers shown.
Illustration of scientists taking ice core samples (©2021 Let’s Talk Science).
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Shown is a colour, comic-style illustration of three people in a snowy landscape, collecting, and looking at ice core samples.

One person holds a tall brown pipe upright in the snow, with both hands. To the right, another person holds a thinner, long, round, light blueish green rod of ice in both hands. They are looking closely at the bottom end. In the foreground, a close-up illustration of this rod shows it has made up of many layers of blue, green, grey and white.

In the background, a third person is working near a jagged, snow covered rock formation. The sky is grey with puffy clouds.


In 1999, Michael Mann and his colleagues published a paper on historical warming alongside more recent trends. Their original finding was that the Earth’s temperature had been fairly stable for around a thousand years. Near the end of the 20th Century, though, temperatures suddenly shot up much higher than they had been previously. This became known as the hockey stick graph.

Comparison of the 'hockey stick graph' and a hockey stick
Comparison of the “Hockey Stick Graph” from the original Nature article in 1999 and a hockey stick (Graph: Klaus Bitterman [BY-SA], Wikimedia Commons; Stick: Jecowa [BY-SA], Wikipedia).
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Shown is a line graph in colour, with an illustration of a hockey stick underneath. The line of the graph has the same curve at the end, as the stick does. 

The x axis of the graph is labelled Year, from 1000 on the left to 2000 on the right. The left y axis is labelled Temperature anomaly (degrees celsius), from -0.8 near the bottom, to 0.6 at the top. The right y axis is labelled Standardized PAGES2K in green. It goes from -4 at the bottom to 6 at the top.

A solid blue line wiggles up and down between -0.5 and -0.1 degrees celsius, until about 1900. A dotted green line wiggles up and down between -1 and 1 on the Standardized PAGES2K scale until about 1900. 

Around 1900, all lines on the graph curve up dramatically, to 0.4 degrees celsius and 5 on the Standardized PAGES2K scale. An additional red line goes from 0 to 5 on the Standardized PAGES2K scale.

Below, the curve of the hockey stick is a bit less dramatic than the curve on the graph.

Effects of Climate Change 

Rising average temperatures can have big effects on climates across the planet. Below are some of the likely effects we’ll see through the rest of the 21st Century.

Longer Warm Seasons

NASA indicates that the western part of North America could see up to eight extra frost-free weeks each year.

This could mean a longer season for growing crops in some places. It also means problems with water availability, since it means less snow and ice in mountainous areas. Snow runoff in the spring is a water source for many reservoirs.

Warmer oceans will also lead to ocean acidification. Fish and other marine life will have a harder time living under these conditions.

Spring runoff of melting snow in the Canadian Rockies
Melting ice in the Canadian Rockies (Source: ImagineGolf via iStockphoto).
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Shown is a colour photograph of thin ice on the edges of a river with mountains in the background. 

There is open water through the centre of the river. In the foreground, the ice is covered with thick snow, but thin and transparent at the edges, over the water and on the rocky shore.

In the background, the sun is setting behind fir trees and a jagged mountain peak. The blue sky is turning golden yellow.


Changing Precipitation

Some places will get more rain and snow than they do now, and other places will get less.

To the right are some models from NASA over what that might look like for the next thirty years.

Predicted changes in precipitation patterns

Predicted precipitation patterns under different climate scenarios (National Climate Assessment and NASA's Goddard Space Flight Center Scientific Visualization Studio).

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Shown is an animated GIF of six maps of North America, where changing colours show changing amounts of precipitation from the year 2015 to 2080.

The maps are laid out on a black background. There are columns labelled Annual, Spring, and Summer, and rows labelled B1 and A2. There is a scale at the bottom labelled Percent Change. It goes from dark brown at -25, through lighter browns and greens to dark green at 25. In the bottom right corner, the years tick forward quickly.

Over time, puddles of green move in from the tops of the maps, and brown moves in from the bottoms. The colours are pale at first, but grow darker quickly. By the end of the loop, most maps are medium and dark green on top and tan with dark brown patches on the bottom. A thin, pale strip remains across the centre of each map.


More Droughts and Heat Waves

Increased temperatures and changing rain and snow patterns will lead to both more droughts, and more heat waves.

Increased drought will mean less water for drinking and for irrigating crops.

Increased heat waves will lead to more health emergencies in the summer including heat stroke, among other things. It will also lead to more wildfires, such as those that devastated Fort MacMurray in 2017 and the B.C. interior in 2021.

Wildfires on a hill above an urban area
Wildfires (Source: Mike Newbry via Unsplash).
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Shown is a colour photograph of a large hill on fire, glowing orange at night, above a town.

In the foreground is a row of buildings along a shoreline, with streetlights in front and a low hill with deciduous trees behind. 

In the background, a hill towers over the landscape. The sky and land are mostly black. A thin stripe of bright orange goes from the base of the hill, up, around and behind it. This lights up the sky and the hill in a hazy orange glow.


More Intense Storms

A major consequence for people living in coastal regions is more storms, and more powerful storms.

The number of powerful Category 4 or 5 hurricanes has increased yearly since the early 1980s.

Warmer oceans lead to “rapid intensification” of hurricanes. This means that they pick up at least 56 km/h (35 miles per hour) in wind speed before they move onto land. This has been rare in the past, but is becoming more common.

Double exposure of Hurricane Ida making landfall
Hurricane Ida approaching New Orleans in 2021 (Source: Brian McGowan via Unsplash)
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Shown is a colour illustration of a hurricane over the water near New Orleans.

In the background, a map of the Louisiana coastline is labelled with place names and temperatures. New Orleans is above the centre of the illustration. Just below it, over the water, is the centre of a spiral. A puff of white curls around a bright turquoise ring, surrounded by another circle of bright turquoise. Blue wraps around that, then purple, pink, yellow, and green curl in uneven, concentric circles to the edge of the map, where the corners are blue again. Thin, pale lines indicate the strength and direction of the wind.


Rising Sea Levels

Sea levels have already risen 20 cm (8”) on average from where they were in 1880. Climate modelling suggests they will rise between 0.3 and 1.01 metres by the end of the 21st Century. Sea levels will continue to rise over the next 2000 years, although the amount depends on how many GHGs are emitted into the atmosphere. 

Rising sea levels will lead to increased incidents of flooding. It will also result in the loss of property and people’s livelihoods.

How does climate change contribute to sea level rise? | Ask A Scientist (3:38) Environment and Climate Change Canada

Decreased Air Quality

Climate change models indicate that air quality will decrease over the next several decades due to two major factors.

First, more wildfires will occur. These wildfires will increase the smoke content in the air.

Second, there will be longer pollen seasons, and more pollen in the air. People with pollen-sensitive allergies and those with asthma will be affected the most by this change to air quality.

Sky full of smoke during the Pine Creek Wildfire, 2012
Sky full of smoke during the Pine Creek Wildfire, 2012 (Source: U.S. Fish and Wildlife Service - Midwest via Flickr).
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Shown is a colour photograph of thick brown, grey and yellow smoke obscuring the sky and sun above trees. 

The sun is high in the sky above the trees, but it looks tiny and glows deep orange, as if at sunset. It's difficult to see the colour of the sky, because it is covered with billowy layers of grey, brown and yellow smoke. In the foreground, trees with leaves appear in silhouette, unburned.


What You Can Do

Climate change is the challenge of our time. While the problems of climate change may seem overwhelming, there are things each of us can do to help provide a solution. The United Nations provides some ideas that, if taken by enough people, may help to lessen the amount of GHGs going into the atmosphere. Below are some of these ideas.

Conserve Energy At Home

It’s helpful to keep in mind how much of your electricity is generated by fossil fuels. Many places still use coal, oil, and natural gas to generate electricity.

Conserving energy means that we must be aware of when we are using electricity when we do not really need to. This can include actions such as turning off the lights when you are not in a room, making sure the fridge door is only open when necessary, and taking shorter showers.

Some places, like Ontario, use a mixture of renewable and nuclear power sources to generate electricity. Even though these sources generate far less GHGs, it is still important to practice good conservation habits.

Wind turbines
Wind turbines on farmland (Source: Gonz DDL via Unsplash).
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Shown is a colour photograph of three wind turbines, in a row, over farmers' fields.

The camera is high in the air in front of the first turbine. The centre of the turbine is clearly visible in the middle left of the photograph, at the top of a long, thin white stem. It is smooth, white and torpedo shaped with a pointed nose. Each of the three long white blades reaches  out to the edge of the frame. Behind this are two identical turbines, forming a line toward the horizon. 

Below are green and brown fields with furrowed  rows and straight edges. This landscape, dotted with green trees, stretches off into haze in the distant background.


Use Your Car Less

Most vehicles on the road use gasoline, which creates GHGs when burned. By walking, biking, or taking public transportation when possible, we can reduce the amount of vehicles on the road. In turn, this will reduce the amount of GHGs we’re putting into the atmosphere.

A bus in London, Ontario
A bus in London, Ontario (Source: RFBailey [CC BY-SA 3.0] via Wikimedia Commons).
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Shown is a colour photograph of a city bus pulled up to a curb.

The bus is white with blue and green stripes down the side and across the front. Within the stripes, block letters L and T form a logo. London Transit is printed above the front passenger door. On the front, a digital sign with orange letters reads 1A Kipp's Lane, Thompson Road. There are tall beige and brown buildings along the street and there is a little snow around a yellow fire hydrant on the sidewalk.


Switch To An Electric Vehicle

Electric vehicles (EVs) or hybrid vehicles are becoming popular choices for those purchasing new vehicles. These types of vehicles create much less GHGs when used.

Electric vehicle charging in a garage near Vancouver
Electric vehicle charging in a garage near Vancouver (dcbel, Unsplash)
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Shown is a colour photograph of a car with a cord running from a white object on the wall, to a panel in its hood. 

The white car is inside a garage painted black, with the door open. A rectangular white box with a black screen is mounted on one wall. A black cord is looped beside it. The other end is plugged into a small, open door at the front of the car's hood.


Eat Your Vegetables

Meat and dairy production creates a large amount of GHGs. Methane, which is 25 times more potent in trapping heat in the atmosphere, is a large byproduct of this production. By cutting down on meat consumption, you can cut down on GHGs.

Eat less meat: Climate report urges change to world food system (3:22) CBC News: The National

Consider Different Travel Options

Airplanes are a major contributor to GHG production. By taking a train, or meeting virtually, you can reduce the amount of GHGs generated by travel.

Train in the countryside
Train in the countryside (Erich Westendarp, Pixabay)
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Shown is a colour photograph of a train with a pointed nose and windowed carriages stretching off into the distance.

Tracks start in the bottom left corner, stretch across a gently rolling green landscape and disappear in the distance. The train is long and grey with dark windows. At the front, the engine is blue and white with a red stripe and pointed nose.


Another important thing you can do is get involved in a STEM career that tackles the problems of climate change head-on. Below are some examples of people who are in the field using STEM to make a difference today.


Climate Atlas of Canada
This site combines interactive mapping, climate modeling, narrative, Indigenous knowledge, and community-based research and video into an interesting way of exploring the effects of climate change and the actions some communities are taking to help provide solutions.

GISGeography - 10 Climate Change Maps - The Climate Explained
This site provides annotated links to several interactive climate change maps that explore the potential effects of climate change on the Earth.

Climate Change 101 with Bill Nye
This video (4:09) from National Geographic explores the basics of climate change with TV scientist Bill Nye.

See what three degrees of global warming looks like
This video (16:23) from The Economist provides a thorough examination of the climate and societal effects of the effects of climate change if carbon emissions continue at their current rate.

Causes and Effects of Climate Change
This video (3:04) from National Geographic provides an overview of the causes and likely effects of climate change on the world.


Agriculture and Agri-Food Canada, Environment and Climate Change Canada, Fisheries and Oceans, and Health Canada (n.d.) Causes and effects of climate change

Anderegg, W. R. L., J. T. Abatzoglou, L. D. L. Anderegg and L. Ziska (2021). Anthropogenic climate change is worsening North American pollen seasons. PNAS 118(7).

Denchak, M. and J. Turrentine (Sept 1, 2021). Global Climate Change: What You Need To Know. Natural Resources Defence Council.

Dickie, Gloria (Oct 13, 2020). The Arctic is in a death spiral. How much longer will it exist? The Guardian.

IPCC (2021). Summary for Policymakers. Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [MassonDelmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press. 

Mann, M. E., R. S. Bradley and M. K. Hughes (1998). Global-scale temperature patterns and climate forcing over the past six centuries. Nature 392: 779-787.

National Oceanic and Atmospheric Administration (2021). Climate change impacts.

Stancil, J. M. (Jun 3, 2019). The Power of One Tree - The Very Air We Breathe. U.S Department of Agriculture.

United Nations Climate Action (n.d.) What Is Climate Change?