Geography · Grade 7 · Living in a Changing Environment · Term 3

Climate Change: Causes and Evidence

Students will investigate the scientific evidence for climate change and the human activities contributing to it.

• Ontario Curriculum Expectations
• ON: Physical Patterns in a Changing World - Grade 7

About This Topic

Climate Change Impacts investigates the geographic consequences of rising global temperatures. Students explore how a warming planet leads to rising sea levels, more frequent extreme weather events, and shifts in agricultural zones. In the Ontario curriculum, this topic is framed through the lens of human-environment interaction, asking how these physical changes will redefine where and how people live.

Students also examine which regions are most vulnerable to these changes, often highlighting that those who have contributed the least to global emissions are often the most affected. This topic particularly benefits from hands-on, student-centered approaches where students can model the impact of melting ice on sea levels or use data to predict future changes in Canada's own biomes through collaborative inquiry.

Key Questions

1. Analyze the scientific evidence supporting the reality of global climate change.
2. Explain how human activities contribute to the greenhouse effect.
3. Differentiate between natural climate variability and human-induced climate change.

Learning Objectives

• Analyze scientific data, such as temperature records and ice core samples, to identify trends supporting global climate change.
• Explain the mechanism by which greenhouse gases trap heat in the atmosphere, using the analogy of a blanket.
• Compare and contrast natural climate fluctuations (e.g., ice ages) with current human-induced warming trends.
• Calculate the potential increase in atmospheric CO2 based on projected fossil fuel consumption rates.
• Identify specific human activities, like deforestation and industrial processes, that contribute to increased greenhouse gas emissions.

Before You Start

Weather vs. Climate

Why: Students need to distinguish between short-term atmospheric conditions (weather) and long-term patterns (climate) to understand climate change.

Earth's Atmosphere

Why: Understanding the composition and basic layers of the atmosphere is foundational to grasping how greenhouse gases function.

Key Vocabulary

Greenhouse Effect	The natural process where certain gases in Earth's atmosphere trap heat, warming the planet. This is essential for life but can be intensified by human activities.
Greenhouse Gases (GHGs)	Gases like carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) that absorb and emit thermal infrared radiation, contributing to the greenhouse effect.
Fossil Fuels	Natural fuels such as coal, oil, and gas, formed in the geological past from the remains of living organisms. Burning them releases large amounts of CO2.
Deforestation	The clearing or removal of forests or stands of trees from land, which is then converted to non-forest use. This reduces the Earth's capacity to absorb CO2.
Climate Variability	Natural fluctuations in climate patterns over time, such as El Niño or volcanic eruptions, distinct from long-term, human-caused climate change.

Watch Out for These Misconceptions

Common Misconception

Global warming means it will be hot everywhere all the time.

What to Teach Instead

Climate change leads to 'climate instability,' meaning more extreme weather of all kinds, including record cold or heavy snow in some areas. Peer discussion of the difference between 'weather' and 'climate' helps clarify this.

Common Misconception

Melting sea ice is the main cause of sea-level rise.

What to Teach Instead

While sea ice melt is a problem, the main drivers are melting land ice (glaciers) and 'thermal expansion' (warm water taking up more space). Hands-on experiments with water temperature help students visualize thermal expansion.

Active Learning Ideas

Simulation Game: The Melting Point

Using two containers of water, one with ice 'on land' (on a rock) and one with ice 'in the water,' students observe which causes the water level to rise as it melts. They then discuss the geographic impact of melting glaciers versus sea ice.

40 min·Small Groups

Gallery Walk: Vulnerability Profiles

Display 'vulnerability cards' for different regions (e.g., the Canadian Arctic, the Maldives, the Sahel). Students move around to identify the primary threat to each region (flooding, permafrost melt, drought) and one way the local people are adapting.

45 min·Small Groups

Think-Pair-Share: Food Security

Show a map of how wheat-growing regions in Canada might shift north as temperatures rise. Students discuss with a partner: Is this a 'good' thing? What are the challenges of farming in the rocky soil of the Canadian Shield?

25 min·Pairs

Real-World Connections

• Climate scientists at Environment and Climate Change Canada analyze satellite data and ground-based measurements to track changes in Arctic sea ice extent and predict future impacts on Canadian ecosystems.
• Urban planners in cities like Toronto are using climate models to design infrastructure that can withstand more frequent extreme weather events, such as intense rainfall and heat waves, ensuring public safety and resilience.
• Agricultural engineers are researching crop varieties that can better tolerate changing temperature and precipitation patterns, informed by data on historical climate shifts and future projections for regions like the Prairies.

Assessment Ideas

Exit Ticket

Provide students with two statements: 1) 'Burning coal for electricity is a natural process that has always happened.' 2) 'The Earth's temperature has always gone up and down.' Ask students to write 'True' or 'False' for each and provide one sentence of scientific reasoning for their answer, referencing greenhouse gases or human activities.

Quick Check

Display images of different human activities (e.g., driving a car, planting a tree, a factory emitting smoke, a solar panel). Ask students to hold up green cards for activities that increase greenhouse gases and red cards for those that decrease them or have no impact. Follow up by asking students to explain their choices for two of the images.

Discussion Prompt

Pose the question: 'Imagine you are explaining the difference between natural climate changes and human-caused climate change to a younger sibling. What are the two most important things you would tell them?' Facilitate a brief class discussion, noting key points on the board.

Frequently Asked Questions

How is climate change affecting Northern Canada?

The Arctic is warming twice as fast as the rest of the planet. This is causing permafrost to melt, which damages buildings and roads, and is changing the migration patterns of animals that Indigenous communities rely on for food and culture.

What is the greenhouse effect?

The greenhouse effect is a natural process where certain gases in the atmosphere trap heat from the sun, keeping the Earth warm enough for life. However, human activities like burning fossil fuels have increased these gases, trapping too much heat.

How can active learning help students understand climate change?

Climate change can feel overwhelming and abstract. Active learning, like modeling sea-level rise or analyzing local weather data, makes the science tangible. It also shifts the focus from 'doom' to 'problem-solving' as students investigate adaptation and mitigation strategies together.

What is climate adaptation?

Adaptation means changing the way we live to deal with the effects of climate change that are already happening. This includes building sea walls, developing drought-resistant crops, or moving infrastructure away from flood-prone areas.