It's hard to spend a winter in Michigan without having an intuitive feel for temperature, but to understand planetary temperatures and greenhouse warming we need a more precise physical meaning. Because the numbers are so large it usually makes sense to talk about average properties. In a cold body, the atoms have relatively low speeds. Temperature is a measure of the average speed of the moving atoms. The faster they jiggle, the higher the temperature.
Temperature is measured in units called degrees.
For science, the most useful scale is the Kelvin scale. There are several types of energy. We cannot create or destroy energy. This is the famous Conservation of Energy Principle . The Temperature of the Early Earth Let's calculate the temperature of the early Earth.