To balance the absorbed incoming energy, the Earth must, on average, radiate the same amount of energy back to space.
cce494 ref666 medieval warm period and little ice age
ref665 Global Radiation Balance Energy balance
The following ignores the Clouds, Albedo, etc. — N.B. Clouds are a major potential variable
The Radiation Balance has been attained at a Global Temperature that allowed human civilisations to develop during the current Interglacial Period — as the result of the Greenhouse Effect.
cce100 — ref636 (see also ref656 from NASA). The above explains how the Greenhouse effect works. The Earth Warmed after the last major Ice Age, initially due to the absorption of Terestrial Radiation by CO2 — as Water Vapour was not prevalent in the cold atmosphere — represented by the 210K infrared spectrum.
The infrared spectrum continued to shift to the 310K spectrum and the current Greenhouse conditions — utilising the gap between CO2 and H2O absorptions. Any further heating would produce increased absorption by H2O and less by CO2.
But how stable is this if as CO2 increases? — and, how does H2O in the form of Clouds affect this? — The indications are that the result is negative feedback due to Water Vapour.
There are 3 separate groups of emissions — The bulk of Balancing Energy radiation from the Earth squeezes through the Main Aperture in the Absorption Spectra of CO2 and H2O Vapour — with some absorption by the Ozone Layer.
The apparently small radiances are associated with smaller apertures — on the left by CO2 and on the right partly CO2 and Water Vapour.Each day our environs are warmed, typically from 5C to 20C — and each night they are cooled. So that the atmosphere and the surfaces are maintained at a minimum of 5C.
cce498 — ref675
Where there are no apertures the radiation is progressively captured by CO2 or H2O vapour — and according to the IPCC this radiation is quickly re-radiated in all directions — the downward radiation back towards the surface and the upward radiation goes through the same process — until it is absorbed by the Atmosphere in a continuing process.
In these parts of the Spectrum additional CO2, or other Greenhouse gases would clearly have no effect!
So, what would be the effect of CO2 increase on the Apertures — can anyone shed light on this?Returning to the Main Aperture.
The lower troposphere is a mix of gases at around 300K — water vapour at up to 4% of the Atmosphere, CO2 & other GHGs, heated by conduction fro the surface, radiation that heats CHGs and radiation that proceeds upwards. The absorbed radiation proceeds to heat the Atmosphere as excited GHGs collide with N2 and O2 .
Fig 496 — ref673 (No diagrams showing CO2 could be found)
There are other versions of Climate Change, for example — ref663 — Global Warming Ozone Depletion theory