Radiative forcing

climate forcingSolar Forcingclimate forcing agentsclimate forcingsexternal forcingsforcingforcingsglobal energy trappinggreenhouse gas forcingnet effect
Radiative forcing or climate forcing is the difference between insolation (sunlight) absorbed by the Earth and energy radiated back to space.wikipedia
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Greenhouse gas

greenhouse gasescarbon emissionsgreenhouse gas emissions
Radiative forcing varies with insolation, the atmospheric concentrations of radiatively active gases, commonly known as greenhouse gases, and aerosols. The radiation balance is altered by such factors as the intensity of solar energy, reflectivity of clouds or gases, absorption by various greenhouse gases or surfaces and heat emission by various materials.
Oxidation of CO to directly produces an unambiguous increase in radiative forcing although the reason is subtle.

Global warming

climate changeglobal climate changeanthropogenic climate change
In the context of climate change, the term "forcing" is restricted to changes in the radiation balance of the surface-troposphere system imposed by external factors, with no changes in stratospheric dynamics, no surface and tropospheric feedbacks in operation (i.e., no secondary effects induced because of changes in tropospheric motions or its thermodynamic state), and no dynamically induced changes in the amount and distribution of atmospheric water (vapour, liquid, and solid forms).
Human activity since the Industrial Revolution has increased the amount of greenhouse gases in the atmosphere, leading to increased radiative forcing from CO 2, methane, tropospheric ozone, CFCs, and nitrous oxide.

Methane

methane gasCH 4 liquid methane
A different formula might apply for other greenhouse gases such as methane and (square-root dependence) or CFCs (linear), with coefficients that may be found e.g. in the IPCC reports.
The Earth's atmospheric methane concentration has increased by about 150% since 1750, and it accounts for 20% of the total radiative forcing from all of the long-lived and globally mixed greenhouse gases.

Greenhouse effect

greenhouse warminggreenhousegreenhouse gases
Because the atmosphere absorbs some of the re-radiated long-wave energy, the planet is warmer than it would be in the absence of the atmosphere: see greenhouse effect.
This increase in radiative forcing from human activity is attributable mainly to increased atmospheric carbon dioxide levels.

Climate sensitivity

Equilibrium climate sensitivity50% increase in atmospheric CO2are net positive
Climate sensitivity is the globally averaged temperature change in response to changes in radiative forcing, which can occur, for instance, due to increased levels of carbon dioxide (CO2).

Global warming potential

global-warming potentialGWP22 times more powerful
Just as radiative forcing provides a simplified means of comparing the various factors that are believed to influence the climate system to one another, global warming potentials (GWPs) are one type of simplified index based upon radiative properties that can be used to estimate the potential future impacts of emissions of different gases upon the climate system in a relative sense.

Albedo

albedosreflectivitygeometrical albedo
Since some radiation is reflected, this must be multiplied by the fraction of incident sunlight that is absorbed, F = (1-R), where R is the reflectivity (albedo) of the Earth —approximately 0.3, so F is approximately equal to 0.7.
The size of this effect is difficult to quantify: the Intergovernmental Panel on Climate Change estimates that the global mean radiative forcing for black carbon aerosols from fossil fuels is +0.2 W m −2, with a range +0.1 to +0.4 W m −2.

Sulfate

sulfatessulphateSO 4
This effect is moderately well understood and leads to a cooling from the negative radiative forcing of about 0.4 W/m 2 relative to pre-industrial values, partially offsetting the larger (about 2.4 W/m 2 ) warming effect of greenhouse gases.

Sunlight

sunshinesolar radiationnatural light
Radiative forcing or climate forcing is the difference between insolation (sunlight) absorbed by the Earth and energy radiated back to space.

Tropopause

at altitudestratospheric stabilitytop of the atmosphere
Radiative forcing is meaningfully quantified at the tropopause and at the top of the stratosphere as flux of watts per square meter of the Earth's surface.

Stratosphere

stratospheric100K feetatmosphere
Radiative forcing is meaningfully quantified at the tropopause and at the top of the stratosphere as flux of watts per square meter of the Earth's surface.

Watt

kWMWmegawatt
Radiative forcing is meaningfully quantified at the tropopause and at the top of the stratosphere as flux of watts per square meter of the Earth's surface.

Metre

metermmetres
Radiative forcing is meaningfully quantified at the tropopause and at the top of the stratosphere as flux of watts per square meter of the Earth's surface.

Solar irradiance

solar radiationinsolationsolar insolation
Radiative forcing varies with insolation, the atmospheric concentrations of radiatively active gases, commonly known as greenhouse gases, and aerosols. Radiative forcing or climate forcing is the difference between insolation (sunlight) absorbed by the Earth and energy radiated back to space.

Concentration

concentrationsanalytical concentrationM
Radiative forcing varies with insolation, the atmospheric concentrations of radiatively active gases, commonly known as greenhouse gases, and aerosols.

Aerosol

aerosolsaerodynamic diameteratomization
Radiative forcing varies with insolation, the atmospheric concentrations of radiatively active gases, commonly known as greenhouse gases, and aerosols.

Climatology

climatologistclimate scienceclimatological
Almost all of the energy that affects Earth's climate is received as radiant energy from the Sun.

Sun

solarSolThe Sun
Almost all of the energy that affects Earth's climate is received as radiant energy from the Sun.

Outgoing longwave radiation

longwave radiationoutgoing radiation emissionslong-wave energy is radiated back
The planet and its atmosphere absorb and reflect some of the energy, while long-wave energy is radiated back into space.

Atmosphere

atmosphericatmospheresplanetary atmospheres
Because the atmosphere absorbs some of the re-radiated long-wave energy, the planet is warmer than it would be in the absence of the atmosphere: see greenhouse effect.

Planet

planetsFormer classification of planetsplanemo
Because the atmosphere absorbs some of the re-radiated long-wave energy, the planet is warmer than it would be in the absence of the atmosphere: see greenhouse effect.

Solar energy

solarsolar-poweredsolar powered
The radiation balance is altered by such factors as the intensity of solar energy, reflectivity of clouds or gases, absorption by various greenhouse gases or surfaces and heat emission by various materials.

Groundcover

ground coverground-covergroundcovers
This happens continuously as sunlight hits the surface, clouds and aerosols form, the concentrations of atmospheric gases vary and seasons alter the groundcover.

Intergovernmental Panel on Climate Change

IPCCIntergovernmental Panel on Climate Change (IPCC)International Panel on Climate Change
A different formula might apply for other greenhouse gases such as methane and (square-root dependence) or CFCs (linear), with coefficients that may be found e.g. in the IPCC reports. The Intergovernmental Panel on Climate Change (IPCC) AR4 report defines radiative forcings as: