Meteorologists study satellite images to determine cloud cover and water vapor in Earth's atmosphere. The long-term pattern of weather that characterizes a region is called climate. Scientists who study climate are called climatologists. Climatologists examine weather patterns and other data from the past in order to make predictions about Earth's overall climate in the future. They make such predictions by creating climate models .
Climate models are sets of mathematical equations.
These mathematical equations describe the relationships among many atmospheric properties, or variables. Such properties include wind speed, air pressure, temperature, precipitation, and the concentrations of many gases in the air. Climate models allow scientists to predict how a change in each variable will affect the other variables and ultimately the global climate on Earth. Climatologists have created a climate model to represent this relationship. They can enter a value for the amount of CO 2 in the air into the mathematical equation of the model.