Calculate the average temperature of Earth. Assume that \(30 \%\) of incident light is reflected. The mean intensity of incident light at the Earth's surface is \(1350 \mathrm{~W} / \mathrm{m}^{2} \mathrm{~K}\).

a. Calculate the average temperature of Earth without the greenhouse effect.

b. Calculate the average temperature of Earth with the greenhouse effect. Assume that \(30 \%\) of the heat radiated by the Earth's surface is trapped by greenhouse gases and cannot escape.