This increase in radiative forcing from human activity is attributable mainly to increased atmospheric carbon dioxide levels.

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.

The GWP is defined as the ratio of the time-integrated radiative forcing from the instantaneous release of 1 kg of a trace substance relative to that of 1 kg of a reference gas:

For those gases, the relative radiative forcing will depend upon abundance and hence upon the future scenario adopted.

Cloud feedback is the coupling between cloudiness and surface air temperature in which a change in radiative forcing perturbs the surface air temperature, leading to a change in clouds, which could then amplify or diminish the initial temperature perturbation.

Cloud forcing ( sometimes described as cloud radiative forcing ) is, in meteorology, the difference between the radiation budget components for average cloud conditions and cloud-free conditions.

These numbers should not be confused with the usual radiative forcing concept, which is for the change in forcing related to climate change.

Trapping of the long-wave radiation due to the presence of clouds reduces the radiative forcing of the greenhouse gases compared to the clear-sky forcing.

Relative to clear skies, clouds reduce the global mean radiative forcing due to CO < sub > 2 </ sub > by about 15 %, that due to CH < sub > 4 </ sub > and N < sub > 2 </ sub > O by about 20 %, and that due to the halocarbons by up to 30 %.

Carbon dioxide is one of the greenhouse gases that enhances radiative forcing and contributes to global warming, causing the average surface temperature of the Earth to rise in response, which the vast majority of climate scientists agree will cause major adverse effects.

At the same time, agriculture has been shown to produce significant effects on climate change, primarily through the production and release of greenhouse gases such as carbon dioxide, methane, and nitrous oxide, but also by altering the Earth's land cover, which can change its ability to absorb or reflect heat and light, thus contributing to radiative forcing.

G Myhre, EJ Highwood, KP Shine, F Stordal 1998 " New estimates of radiative forcing due to well mixed greenhouse gases " Geophysical Research Letters, Volume 25, Issue 14, p. 2715-2718. abstract

" The effect of human activity on radiative forcing of climate change: a review of recent developments " Global and Planetary Change, Volume 20, Issue 4, May 1999, Pages 205-225.

The physical effect of CO < sub > 2 </ sub > in the atmosphere can be measured as a change in the Earth-atmosphere system's energy balance – the radiative forcing of CO < sub > 2 </ sub >.

This effect is moderately well understood and leads to a cooling from the negative radiative forcing of about 0. 5 W / m < sup > 2 </ sup > relative to pre-industrial values, partially offsetting the larger ( about 2. 4 W / m < sup > 2 </ sup >) warming effect of greenhouse gases.

This airborne dust is considered an aerosol and once in the atmosphere, it can produce strong local radiative forcing.

This is known as solar forcing ( an example of radiative forcing ).

In climate science, radiative forcing is generally defined as the change in net irradiance between different layers of the atmosphere.

Typically, radiative forcing is quantified at the tropopause in units of watts per square meter.

Materials commonly used in urban areas for pavement and roofs, such as concrete and asphalt, have significantly different thermal bulk properties ( including heat capacity and thermal conductivity ) and surface radiative properties ( albedo and emissivity ) than the surrounding rural areas.

Although climate sensitivity is usually used in the context of radiative forcing by carbon dioxide, it is thought of as a general property of the climate system: the change in surface air temperature ( ΔT < sub > s </ sub >) following a unit change in radiative forcing ( RF ), and thus is expressed in units of ° C /( W / m < sup > 2 </ sup >).

This oscillating dipole moment is responsible for the phenomenon of radiative transition between quantum states of a charged particle.

where is the total decay rate, the radiative decay rate and the non-radiative decay rate.

* The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths, largely in the range 0. 2 – 4 μm, corresponding to the Sun's radiative temperature of 6, 000 K. Almost half the radiation is in the form of " visible " light, which our eyes are adapted to use.

The observed state of gas within a cluster is determined by a combination of shock heating during accretion, radiative cooling, and thermal feedback triggered by that cooling.

GWP is based on a number of factors, including the radiative efficiency ( infrared-absorbing ability ) of each gas relative to that of carbon dioxide, as well as the decay rate of each gas ( the amount removed from the atmosphere over a given number of years ) relative to that of carbon dioxide.

where TH is the time horizon over which the calculation is considered ; a < sub > x </ sub > is the radiative efficiency due to a unit increase in atmospheric abundance of the substance ( i. e., Wm < sup >− 2 </ sup > kg < sup >− 1 </ sup >) and is the time-dependent decay in abundance of the substance following an instantaneous release of it at time t = 0.

The allowed transitions are described by so-called selection rules, which describe the conditions under which a radiative transition is allowed.

In this context radiosity is the total radiative flux ( both reflected and re-radiated ) leaving a surface, also sometimes known as radiant exitance.

* Absorption occurs when energy from the radiative source is absorbed by the material.

* Emission indicates that radiative energy is released by the material.

* Coherent or resonance spectroscopy are techniques where the radiative energy couples two quantum states of the material in a coherent interaction that is sustained by the radiating field.

where is the initial number of light sources in the excited state, is the time and is the radiative decay rate of the transition.

The radiative decay rate is inversely proportional to the lifetime:

In this case one speaks of full radiative decay and this means that the quantum efficiency is 100 %.

Besides radiative decay, which occurs under the emission of light, there is a second decay mechanism ; nonradiative decay.

where is the total decay rate, is the radiative decay rate and the nonradiative decay rate.

The total solar irradiance ( TSI ) is the amount of solar radiative energy incident on the Earth's upper atmosphere.

For the case of a change in solar irradiance ( i. e., " solar forcing "), the radiative forcing is simply the change in the average amount of solar energy absorbed per square meter of the Earth's area.

The number and type of CCNs can affect the lifetimes and radiative properties of clouds as well as the amount and hence have an influence on climate change ; the details of this are still not well understood but are the subject of research.

For a nearby object emitting a given amount of light, radiative flux decreases with the square of the distance to the object, but the physical area corresponding to a given solid angle ( e. g. 1 square arcsecond ) increases in the same fashion, resulting in the same surface brightness.

* Total solar irradiance ( TSI ), the amount of solar radiative energy incident on the Earth's upper atmosphere