Earth radiation budget

A conserved quantity called "energy" exists (the first law of thermodynamics)
Kinds of energy
Mechanical energy
Kinetic energy (energy associated with motion)
Potential energy (energy associated with position)
Internal energy
"Sensible heat" (Δenergy = heat capacity × Δtemperature)
"Latent heat" related to phase change (gas, liquid, solid)
Exchange of energy
Work = force × distance
Conduction of heat
Convection (advection)
... energy transport associated with movement of matter (mass)
Radiation ... energy transport associated with electromagnetic waves
Units of energy and related quantities
Energy, work: SI unit is J (joule) (= N m).
Energy per unit time (energy flux, power): W (watt) (= J / s).
Eenrgy per unit time per unit area (energy flux density): W / m^2.