We humans are changing the composition of the atmosphere in many ways. Those changes will directly affect the planet’s temperature, but the resulting change in temperature will affect other things on the planet that also affect the planet’s temperature. Suppose that we could magically change the composition of the atmosphere enough to raise the temperature one degree if all other parts of the earth system were held fixed, and after the warming, we allowed the other parts of the earth system to react for a few years or decades. At the end of that time, what would be the total change in the earth’s temperature?.