While some are arguing that global warming is a completely natural process and that there's nothing to worry about, most scientists agree that human actions are a major contributing factor.

With each passing year, the Earth's average surface temperature is increasing. This is mainly due to the release of CO2 and other greenhouse gases caused by humans. The greatest amount of greenhouse gas is produced by the burning of fossil fuels such as coal, oil and gas and human daily activities, including operating a motorbike that uses petroleum, cutting down and burning trees, and manufacturing everything we need.

The impacts of global warming are foreseeable. Global warming will cause polar ice melting. When sea levels rise, some animals and plants will lose their habitats and be killed. We will lose certain precious sources of food. In other words, we will be seriously affected if nothing's done to stop global warming. Global warming will also force people in coastal areas to lose their homes. Not worried? Even if you live thousands of kilometers inland, you may still suffer from floods, land erosion, excessive snow or desertification!

While others are arguing about whether humans are the only ones causing global warming, we should take action! Turn off electrical devices you're not using, walk or use your bike if your journey is short, and save water when you take a bath or do the washing. We've all heard the advice given by scientists and environmental groups, but these above are simple things that you don't need to work for NASA or any environmental protection organisations to know what to do.