 So the temperature of the atmosphere has an interesting behaviour and it varies depending which layer we're talking about. So in the troposphere where we live, temperature generally decreases with altitude. So up to about 12 kilometres into the Earth's atmosphere, as you move up, you'll experience colder and colder temperatures. Then something very interesting happens from about 12 kilometres to about 20 kilometres where the temperature doesn't change very much. And that's into the stratosphere and from there on the stratosphere temperature increases with altitude. Now the funny thing there is that's because of ozone. Ozone, that critically important gas that protects us from the sun's harmful UV rays, that absorbs the solar energy and because it's a gas absorbing energy it heats up. So that's why the temperature in the stratosphere increases with altitude. But then as you move up the layers into the mesosphere temperature decreases again. And by the time you get into the thermosphere there's very little atmosphere to protect us from sun's light so temperature increases with altitude.