[PDF] provide a source and the sign of the radiative forcing.

What causes radiative forcing?

The causes of such a change may include changes in the sun, clouds, ice, greenhouse gases, volcanic activity, and other agents. Radiative forcing is often specified as the net change in energy flux at the troposphere (watts per square meter). Radiative forcing may sometimes be referred to as external forcing or perturbations of the climate.

What is radiative forcing based on watts per square meter?

This figure shows the amount of radiative forcing caused by various greenhouse gases, based on the change in concentration of these gases in the Earth’s atmosphere since 1750. Radiative forcing is calculated in watts per square meter, which represents the size of the energy imbalance in the atmosphere.

What is the difference between positive and negative radiative forcing?

Positive radiative forcing means Earth receives more incoming energy from sunlight than it radiates to space. This net gain of energy will cause warming. Conversely, negative radiative forcing means that Earth loses more energy to space than it receives from the Sun, which produces cooling.

What is net effective radiative forcing?

The resulting net effective radiative forcing is a positive net forcing of the climate system and hence a warming, but the uncertainties in the probability density function of atmospheric aerosols feeds through to cause a far greater uncertainty in the net radiative forcing of climate than if only greenhouse gases were considered.