Earth’s Energy Budget

The earth works in an equilibrium. It strives to maintain an overall budget between the overall amount of incoming and outgoing energy at the top of the atmosphere.

Earth receives incoming energy from the Sun. Earth also emits energy back to space. For Earth’s temperature to be stable over long periods of time (for the energy budget to be in balance), the amount of incoming energy and outgoing energy must be equal.

If incoming energy is more than outgoing energy, Earth will warm. If outgoing energy is greater than incoming energy, Earth will cool.

Source: NASA

While there are natural tendencies of the Earth to have simultaneous periods of cooling and warming.
Those periods have in the past been spread out over thousands of years.
Unlike the recent bout of heating that has affected since the late 19th century due to the excessive burning of fossil fuels and trapping of greenhouse gases.
In the photo here, you can see the average temperature increase has been about 1 degree celsius since the base period of 1951-1980. Since the late 19th century, the heating is at about 1.2 degrees of pre-industrial levels
Scientists estimate that exceeding 1.5 degrees would lead to mass scale agricultural crop loss, drought, cyclones, forest fires and more.

Source: NASA, IPCC AR6