Some scientists say that the weather in the future won't be good. Summers will be hotter. Warmer, wetter winters are on the way. Terrible droughts (干旱), floods, wildfires, and storms may often happen.
What's the reason for all those wacky weather changes?
Global warming causes (导致) some weather changes. Global warming happens when gases in the air take in the Sun's energy. That energy heats the Earth. Without the gases, the energy would go into space. Some global warming is good. Without it, the Earth would be too cold to live on.
For years, humans make lots of pollution. Pollution is one of the reasons for global warming.
There are some signs (迹象) of global warming. One of the signs is happening in the coldest parts of the world. Near the North and South Poles, large ice sheets (冰原) are breaking up. Scientists think some may disappear by the year 2100.
Because the ice melts, ocean levels rise. This might cause floods.
In some areas, global warming might cause droughts. Droughts may cause wildfires.
Scientists say that cutting down air pollution will slow global warming. One way to lower air pollution is to drive less. People also need to find cleaner ways to make electricity.
