Heatwaves, droughts, floods, and storms are all extreme weather conditions. A heat wave is very hot weather that lasts for days, and a drought is very little rain for an extended period of time. Extreme weather can cause great damage to buildings and roads, people and animals. Damage caused by extreme weather can cost billions of dollars and many people could die.
Some gases in the atmosphere are called greenhouse gases because they keep the Earth warm, like glass in a greenhouse. They do this by preventing some of the Sun's heat from leaving Earth.