Britannica
Sources used in this answer
What is the difference between positive and negative radiative forcing?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
Global warming
A series of photographs of the Grinnell Glacier taken from the summit of Mount Gould in Glacier National Park, Montana, in (from left) 1938, 1981, 1998, and 2006. In 1938 the Grinnell Glacier filled the entire area at the bottom of the image. By 2006 it had largely disappeared from this view.
Radiative forcing is a measure of how specific climatic factors influence the amount of downward-directed radiant energy reaching Earth’s surface. These factors, which can be natural or anthropogenic, are categorized by their effect on surface temperature:21
- Positive forcing: Exerted by factors that contribute to the warming of Earth’s surface. An example includes the increase in greenhouse gases like carbon dioxide and methane, which trap heat in the atmosphere.21
- Negative forcing: Exerted by factors that cool Earth’s surface. A natural example is the release of gases and ash during volcanic eruptions, which can block incoming solar radiation.21
By calculating these values relative to 1750 benchmark levels, scientists can determine the net influence of human activities on the climate since the Industrial Revolution.21