The effect of this disparity is that
thermal radiation escaping to space comes mostly from the cold upper atmosphere, while the surface is maintained at a substantially warmer temperature.
As the concentration of greenhouse gases in the atmosphere increases, we expect to see less infrared
radiation escaping at the top of the atmosphere.
The visible solar radiation mostly heats the surface, not the atmosphere, whereas most of the
infrared radiation escaping to space is emitted from the upper atmosphere, not the surface.
Such atmospheres slow down rate at which
radiation escapes from the surface to space: from 390 W / m2 to 240 W / m2 on Earth, and from 16,700 W / m2 to 65 W / m2 on Venus.
So with more carbon dioxide in the atmosphere, we expect to see less
longwave radiation escaping to space at the wavelengths that carbon dioxide absorb.
The latest modelling experiments take this into account, but it is easier to understand causes and effects in an equilibrium - response experiment.The first thing that happens when CO2 is doubled is that less energy in the form
of radiation escapes to space.
When present, the gases don't
let radiation escape from Earth as easily, forcing the equilibrium temperature to become higher.
The fact that carbon dioxide is a «greenhouse gas» - a gas that prevents a certain amount of heat
radiation escaping back to space and thus maintains a generally warm climate on Earth, goes back to an idea that was first conceived, though not specifically with respect to CO2, nearly 200 years ago.
It lets light through from the Sun that heats the ground, but then won't let the thermal infrared
radiation escape into space.
If this finding holds up, we may have to reevaluate the numbers of known stars in a galaxy, how much mass the stars contain, and how
much radiation escapes a galaxy.
A recent paper by Lindzen and Choi in GRL (2009)(LC09) purported to demonstrate that climate had a strong negative feedback and that climate models are quite wrong in their relationships between changes in surface temperature and corresponding changes in
outgoing radiation escaping to space.
Because the lapse rate is not zero, changing the altitude near the top of the atmosphere where infrared
radiation escapes freely to space allows adjustment of the surface temperature by means of the addition of greenhouse gases.
At about 90 km up, I note that the atmosphere of Venus cools down to very low temperatures in the vicinity of -112 deg C. I suspect this is the CO2 thermal
radiation escape altitude there.
The problem is that even though scientists can easily measure the former, they have not ever been able to accurately measure the latter — because the outgoing infrared
radiation escapes from the full 360 degrees of the planet's surface.
What * does * drive warming is that, as the mean free path length of thermal radiation shortens, the mean altitude at
which radiation escapes to space rises.
This matters because clouds are fundamental regulators of how much solar radiation makes it to the Earth's surface (rather than being reflected back to space by white cloud tops), and how much infrared or «longwave»
radiation escapes back to space once again.
The evidence here comes from satellite measurements of
infrared radiation escaping from the earth into outer space, from measurements of sunlight reflected from clouds and from measurements of the temperature the earth's surface or of the troposphere, the roughly 10 km thick layer of the atmosphere above the earth's surface that is filled with churning air and clouds, heated from below at the earth's surface, and cooled at the top by radiation into space.
Theoretical physicists have come up with three possibilities: something happens to stop the black hole evaporating away; the information really is lost (perhaps «tunnelling» into another universe); or
the radiation escaping from the evaporating black hole must carry information away with it.
The household product was used to absorb liquid in radioactive debris at a waste disposal site in New Mexico where
a radiation escaped to the surface and exposed 21 workers
Ozone within the troposphere is an increasingly important greenhouse gas, stopping infrared
radiation escaping to space.
Much of
this radiation escapes as infrared.
Therefore, if you work from the layer at which
the radiation escapes into space (about 6 km) down to the ground, the negative lapse rate means that surface temperature has to be higher than the non-GHG temperature.
No radiation escaped, and no one died.
It also means less longwave
radiation escaping to space.
The visible solar radiation mostly heats the surface, not the atmosphere, whereas most of the infrared
radiation escaping to space is emitted from the upper atmosphere, not the surface.
This interpretation is essentially the converse of the point (made years earlier by Nils Ekholm) that
radiation escaping the atmosphere is controlled by the effective altitude of the radiating layer.