Unit 18 Climate Change Wipes Out Frogs
Global warming is an increase in the Earth’s temperature. Some gases, including carbon dioxide and methane, trap the Sun’s heat. They are known as greenhouse gases. An increase in greenhouse gases has caused global warming.
Layer of greenhouse gases
Trapped heat
Heat
Sun
Heat that escapes the Earth’s atmosphere
Greenhouse gases trap energy in the atmosphere and make the Earth warmer.
1 Why is the fungus spreading? 2 In what areas of the world are frogs affected? 3 How many amphibians in the world are affected? a) more than half c) less than a quarter b) a quarter d) almost a third
4 Why is the research important? 5 Name two greenhouse gases.
6 What do the arrows in the diagram tell us? 7 What, according to scientists, is the cause of global warming?
• Reading: Ask students to identify verbs in the passive voice. Remind them that the passive voice is common in expository texts. • Look online for more information to share with the class. Find child-friendly sites that they can look at, for example, https://climatekids.nasa.gov/. ICT If students have questions or want to know more about a topic, suggest they write questions in their journals. At home, or in the library, they can research online to find answers. Now you know what climate change means for frogs… but what does climate change mean for us? The future If the climate gets warmer, sea levels will rise because: • glaciers and ice sheets will melt • as water gets warmer, it expands and takes up more space. Why does it matter? If sea levels rise, towns and villages near the sea will flood more frequently or be submerged completely. Rising sea level would also harm mangrove forests and coral reefs which protect our coastlines. Hurricanes get their energy from warm ocean water. If the top layer of water gets warmer, hurricanes will grow stronger, with faster winds and heavier rain. Hurricanes already damage people’s homes and take away their livelihoods; stronger, more frequent ones will bring more devastation.
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