Presentation on theme: "GLOBAL WARMING SEKOLAH MENENGAH PERSENDIRIAN HAN CHIANG Incorporation with MAJLIS PERBANDARAN PULAU PINANG Prepared By : Margaret & Malathi."— Presentation transcript:
GLOBAL WARMING SEKOLAH MENENGAH PERSENDIRIAN HAN CHIANG Incorporation with MAJLIS PERBANDARAN PULAU PINANG Prepared By : Margaret & Malathi
Earth’s Atmosphere Earth’s atmosphere is a layer of gases surrounding the planet earth and retained by the Earth’s gravity. It contains roughly nitrogen, oxygen, carbon dioxide, trace amounts of the other gases, and a variable amount of water vapour. This mixture of gases is commonly known as air. The atmosphere protects life on Earth by absorbing between day and night.
What is global warming? It is the rise of the temperature of the earth’s atmosphere
What causes global warming? There is a layer of gases surrounding the earth. They are all natural greenhouse gases. But human beings make extra greenhouse gases from pollution – smoke from factories, vehicles, cutting down trees, use of chemical sprays and so on.
Examples causes of global warming smoke from factories smoke from vehicles
cutting down trees use of chemical sprays
Green House Effect is caused by green house gasses. Greenhouse gases are like a blanket. If they are the right thickness, the earth can maintain its liveable temperature. Many experts now thin the way we burning fossil fuel and adding chemicals to the atmosphere is causing the blanket to become thicker. This makes Earth warmer, an effect known as Global Warming.
The earth and its atmosphere is like a greenhouse. When the sun shines, it keeps the earth warm because 70% of the heat stays in the atmosphere (like a blanket). About 30% of the heat goes back into space.
Is global warming bad? Some global warming is good. But if the layer of greenhouse gases gets thicker, heat from the sun cannot escape and too much heat stays in the earth’s atmosphere. That’s when global warming is bad.
What happens after that? Glaciers and ice will melt and sea levels will rise. This may cause flooding in cities along the coast.
Lakes and rivers could dry up
Crops can’t grow because of drought (no rain for a long period of time)
People and animals starve because there is not enough food.
Some plants and animals become extinct (die out completely ) because of the heat.
World weather patterns will change – more hurricanes & tornadoes, droughts and so on