What is global warming?
Global warming is the gradual increase in the average temperature of the Earth's atmosphere and oceans. It happens because certain gases in the atmosphere trap heat from the Sun. This trapping of heat is called the greenhouse effect. A natural greenhouse effect keeps the Earth warm enough for life, but human activities are making it too strong.
Key idea
Greenhouse gases such as carbon dioxide (CO2), methane and water vapour let sunlight in but trap the heat that tries to escape, warming the planet. More greenhouse gas = more warming.
Causes
- Burning fossil fuels (coal, oil, gas) for electricity and transport releases carbon dioxide.
- Deforestation removes trees that absorb carbon dioxide.
- Industry and farming release gases such as methane.
Effects
- Melting glaciers and polar ice, causing sea levels to rise and low islands to flood.
- More extreme weather: stronger storms, droughts and heatwaves.
- Changing rainfall patterns that harm farming and water supplies.
- Harm to plants and animals as habitats change.
Example
As glaciers and Arctic ice melt, seawater expands and rises, threatening low-lying coasts and small islands in the Pacific with flooding.
What we can do
People can slow global warming by saving energy, using renewable sources like solar and wind, planting trees, recycling and using public transport. Governments sign agreements to cut greenhouse gas emissions.
Remember
- Greenhouse gases trap heat and warm the Earth.
- Carbon dioxide from burning fossil fuels is a major cause.
- Effects include melting ice, rising seas and extreme weather.