A climate forcing can be defined as an event that changes and disturbs the Earth’s energy balance [21]. A common classification of climate forcings is whether the forcings are natural or human-made. An example of a natural climate forcing for Earth is a sudden change of brightness from the sun, while an example of a human-made forcing is a human-made gas. One of these human-made gases is the added concentration of carbon dioxide in the atmosphere due to the burning of fossil fuels. Both of these examples change the Earth’s energy balance.
