Question

How much extra heat would be in the earths atmosphere if the average temperature of the earth increased by 1 degree Celsius.

Answer 1

It might depend on the reason why the earth had become warmer. Was it from a heating up of the core of the earth? Or was it via sunlight passing through the atmosphere to warm the surface of the earth? Also important would be how the heat was distributed in the mass of the earth.

Answer 2

that depends strongly on the amount of air present.