What is climate change? The word climate means the average weather conditions over a number of years, including temperature, wind, and rainfall. When we talk about climate change, we mean the unusual changes in the Earth's weather patterns that have happened over the last 100 years. It is true that the weather is always changes, and sometimes the weather changes in ways we really don't expect For example, we might have a warm, sunny day in the middle of winter, or a cold, windy day in the middle of summer Recording the temperatures of each day helps us find the average temperature for the whole year. Doing this in many different parts of the world lets us find the average global temperature. When all temperatures are taken together, we would expect any ups and downs in the year to cancel each other out, and the average temperature to stay roughly the same from one year to the next. However, scientists have found that the temperature is not staying the same, and our planet is actually getting warmer each year. This is called global warming, and it is a major part of climate change. Extreme changes in climate are nothing new on Earth. In its long history, there have been times when the Earth's climate became warmer, causing ice to melt and sea levels to rise, so that much more of our planet was covered in water At other times the Earth has been very cold, these ice ages saw huge areas of the planet cowered in snow and ice. These might sound like drastic changes in the Earth's climate, but they happened very gradually over thousands of years