The transfer of heat energy by molecular and electron collisions within a substance (especially a solid)
The transfer of heat energy in a gas or liquid by means of currents in the heated fluid. The fluid moves, carrying energy with it.
The transfer of energy by means of electromagnetic waves.
The radiation emitted by Earth to outer space.
Newton's Law of Cooling
The rate of loss of heat from a warm object is proportional to the temperature difference between the object and its surroundings.
Warming of the lower atmosphere by short-wavelength radiation from the Sun that penetrates the atmosphere, is absorbed by Earth, and is re-radiating at longer wavelengths that cannot easily escape Earth's atmosphere.
W1400 J/m^2 received from the sun each second at the top of Earth's atmosphere on an area perpendicular to the Sun's rays; expressed in terms of power, 1.4 kW/m^2