Question

What is radiative forcing? Describe some warming and cooling forcing agents.

Short answer

Radiative forcing is the difference between sunlight absorbed by Earth and energy radiated back into space. Warming forcing agents (positive radiative forcings) such as greenhouse gases trap heat from the Earth's surface, leading to warming. Cooling forcing agents (negative radiative forcings) like aerosols and changes that increase Earth's albedo, such as deforestation, reflect more sunlight back into space, leading to cooling.

Step-by-step solution

Define Radiative Forcing

Radiative forcing is the difference between insolation (sunlight) absorbed by the Earth and energy radiated back into space. Changes in factors that cause insolation or energy radiation can lead to changes in the earth's climate system.

Identify Warming Forcing Agents

Warming forcing agents or positive radiative forcings, lead to warming of our planet. This happens when they result in more energy being added to the earth’s system than being radiated back into space. Examples include greenhouse gases like carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), which trap heat from the Earth's surface that would otherwise escape into space.

Identify Cooling Forcing Agents

Cooling forcing agents or negative radiative forcings, lead to cooling of the earth. This happens when they result in more energy being radiated back into space than being added to the earth’s system. Examples include aerosols (tiny particles in the atmosphere) which reflect sunlight back into space, cloud changes that increase earth's albedo (reflectivity), and changes in land use that increase earth's albedo such as deforestation.