Climate change is when the Earth's temperature becomes warmer over time. This is because people are doing things that make too much pollution. Pollution is like litter, but in the air. This pollution is trapping too much heat from the sun and making the Earth get warmer.
When the Earth gets warmer, lots of things could happen. Sea levels could rise, which means that the water in the ocean gets higher and could cover up land where people live. This would make it hard for people to live there anymore. Also, the weather could get a lot more extreme. There could be more hurricanes, floods, and droughts. This means it will be harder to grow food and some places might not have enough water.
We need to work together as a planet to stop pollution and make the Earth cooler again. This is called "fighting climate change." We can do things like use clean energy instead of burning things that make pollution, like oil and coal. We also need to try to use less energy and recycle more things, like plastic, to produce less waste. These things are important because if we don't start fighting climate change now, it could become too hard or too late to fix all the problems it causes.