1.2  Climate change: Human activities VS natural climate variations?

Information for Planning & Teaching

Background Knowledge 

1.What is climate change and what causes it? 

Climate change describes significant, long-term changes in Earth's temperature and weather systems. While natural factors like solar fluctuations and volcanic activity have historically influenced climate patterns, human activities (burning of fossil fuels like coal, oil and gas) have become the dominant cause of climate change since the Industrial Revolution (around the 1800s).

When we burn fossil fuels for energy invisible gases are released into the atmosphere. These greenhouse gases—primarily carbon dioxide (CO₂) and methane (CH₄)—act like a thick blanket wrapped around the Earth. Just as a blanket traps body heat to keep you warm, these gases trap the sun's energy, causing our planet's temperature to rise over time. The carbon dioxide in our atmosphere mainly comes from everyday human activities. For example, when we drive cars that run on gasoline or use coal to heat our homes and power our cities, we release CO₂ into the air. Another significant source is deforestation—when we cut down forests, we lose trees that naturally absorb CO₂, leaving more of this heat-trapping gas in the atmosphere. Methane is another powerful greenhouse gas, and it comes from sources like agriculture (especially from livestock like cows and from rice farming) and leaks in oil and gas operations. Though methane doesn’t stay in the air as long as CO₂, it traps much more heat in the short term, making it a major contributor to global warming.

Lesson Timing: This lesson needs preliminary knowledge learned from lesson 1.1. 

Student Ideas & Experiences: Students can understand sources of greenhouse gases through everyday examples, such as transportation, home energy use, food production, manufacturing and industry, and so on. These experiences may have been connected in the lesson 1.1. This can reinforce the idea that human activities primarily cause the climate change.  

Science Practices: Argumentation. In this lesson, students are introduced two alternative explanations of climate change and corresponding evidence from different sources. Students need to identify the relationships between the claims and evidence by drawing supporting or contradicting arrows and explain how. Integrating Evidence-Claim-Link (ECL) diagram and scaffolding multiple choice questions can help students combine their data analysis with evidence-based arguments construction.

Teaching Cases