As is now generally known, there has been no warming of the Earth’s surface since 1998 at least.  Prior to that time, we were informed that there had been a rapid warming of the Earth’s surface and that it was caused by increasing carbon dioxide (CO2) concentrations in the atmosphere due to man using fossil fuels. 

The 2007 Intergovernmental Panel on Climate Change (IPCC) 4th Report still insisted that for 25 years the Earth had been warming.  A newly published study using satellite temperature sensing specifically for detecting the Earth’s surface temperature and minimizing that of the atmosphere above the surface, shows that the Earth’s surface, contrary to reports, actually cooled from 1982 to 2006!

The paper is entitled Meteosat Derived Planetary Temperature Trend 1982-2006 by Andries Rosema, Steven Foppes, and Joost van der Woerd and was published in Energy & Environment, Vol. 24, No. 3 & 4 2013.  They were very surprised to find the cooling trend they reported. Earlier satellite data analyses, originated by investigators at the University of Alabama at Huntsville, used microwave sensors to infer the temperature from microwave emissions from oxygen molecules. 

Microwaves of different energies originated from various layers of the atmosphere.  One set of data originated from an altitude of about 17 km.  Another at an altitude of about 3 – 4 km. Then by looking at data taken at oblique angles of incidence, they inferred a temperature from an altitude of about 0.8 km.  However, none of this data actually measures the Earth’s surface temperature.  Initially, this data on the lower atmosphere had shown a small cooling effect, but after many corrections were applied, the data yielded an increase of temperature of about 0.1 C/decade in the troposphere.  The troposphere is the bottom about 10 to 11 km of the atmosphere and its temperature is not at all necessarily in direct proportion to the surface temperature.  Indeed, increased cloud cover, water vapor, and CO2 in the atmosphere may cause an increase in the troposphere temperature even as it cools the surface temperature.

One of the significant errors commonly made by the advocates of catastrophic man-made global warming due to CO₂ emissions is the claim by the settled science proclaimers that radiation from a non-vacuum interface is the same as radiation from a surface into a vacuum. This error in the physics of radiation from the Earth’s surface results in an exaggeration of the cooling radiation emitted from the Earth’s surface and contributes to them positing a hugely larger back-radiation from greenhouse gases than can actually occur.

I have previously pointed out that the Stefan-Boltzmann Law actually only tells us the amount of radiation emitted by a surface into a vacuum. A surface in contact with another material will lose energy by other mechanisms, so one must apply the law of Conservation of Energy to determine the actual amount of radiation in many cases of material contact across an interface. In the case of the Earth’s surface, water is evaporated at the surface with a very substantial cooling effect. In addition, air molecules strike the surface and carry away heat gained in collisions with the surface. Despite these obvious problems with an unchanged surface emission of radiant energy into the atmosphere compared to that into a vacuum, the settled science proclaimers have in many cases steadfastly said that I am wrong. OK, so I will try to explain this in greater detail in this post.

It is commonly said that because the radiative power from the Earth system into space is the same as that of a black body with a temperature of about 255K and the observed average temperature of the Earth’s surface is about 14.5ºC or 287.65K, the surface of the Earth is nearly 33K warmer than it would be if there were no greenhouse effect.  The greenhouse effect is said to be due to infra-red active gases such as water vapor, carbon dioxide, methane gas, and nitrous oxide.

The problem with this argument is that while the Earth system is in radiative equilibrium with space, the surface of the Earth is not.  Thus, there is a complex relationship between the equilibrium temperature of the Earth’s surface and its equivalent radiative temperature as a black body radiator.  Some of the radiation into space is direct from the Earth’s surface, but most of it is from the infra-red active gases of the many layers of the atmosphere.

I have previously shown that the infra-red gases probably produce more cooling than warming.  Those arguments were not simple enough for most people to follow and they did not show what the amount of cooling of the Earth’s surface actually was.  I am going to show a surprisingly simple proof in this article that the infra-red gases, commonly called greenhouse gases, cause the surface temperature of the Earth to be much cooler than it would be if our atmosphere had no infra-red active gases in it.

Consider the following NASA energy budget of the Earth:

As I have discussed in an article called The Unsettled Earth Energy Budget, one should add a small amount of energy absorbed by the Earth’s surface due to back-radiation from the atmosphere.  My estimate for that back-radiation is about 1 to 2{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} of the solar insolation radiation at the top of the atmosphere.  Since other NASA Earth energy budgets put the amount of energy absorbed from the direct solar insolation at 48 or 49{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117}, let us only add the 1{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} back-radiation amount to the 51{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} absorbed solar insolation shown above.  In 2010, the average top of the atmosphere solar insolation was 1365.8 W/m².  The average solar insolation over the day at a spot on the rotating Earth is one-quarter this amount.

At equilibrium, the power absorbed by the Earth’s surface equals the power emitted by the Earth’s surface.  If the Earth’s surface were an interface with vacuum, the total emitted power is given by the Stefan-Boltzmann Law and we have the equilibrium condition:

P_abs = ε σ T⁴,

Where ε is the Earth’s surface emissivity, σ = 5.6697 x 10^-8 W/m²K⁴, and T is the average surface temperature of the Earth.  Thus we have:

P_abs = (1365.8/4)(0.52) = ε (5.6697 x 10^-8 W/m²K⁴)(287.65K)⁴

Solving the equation for ε, we find:

ε = 0.457

This is an emissivity somewhat less than half what most commonly is claimed for the Earth’s surface.

It is common to claim that emissivity is nearly black body-like, with 0.95 < ε < 0.98.  The claim is also made that like a near black body, the Earth both absorbs and emits a continuum of infra-red radiation in the mid- and far-infra-red ranges characteristic of a black body radiator with a temperature somewhere between 220 and 360K.  It is claimed that the absorptivity and the emissivity are matched as they would be in a black body radiator.  Yet, infra-red spectroscopy in the laboratory on common laboratory FTIR spectrometers show that the absorption spectra of water, minerals, soil, and plant materials are not at all similar to that of a black body.  The very characteristic spectra of these materials are used to identify them or similar materials.  Yet, there are those who claim that the emissivity of water which covers 71{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} of the Earth’s surface is in this near black body range and that so are the emissivity and absorptivity of most organic materials, such as plant materials.  Such a claim is inconsistent with the NASA Earth energy budget shown in the diagram above.

An examination of the energy budgets for the Earth of recent years gives one reason to be unsettled about the settled science claimed for the catastrophic man-made global warming hypothesis.  The energy budget currently posted by NASA is shown in Figure 1 below.

Figure 1 shows the principal NASA energy budget for the Earth as of February 2013.  Note the huge surface radiation and the huge radiation from the atmosphere all of which is absorbed by the surface.  The surface-absorbed atmospheric down radiation is 100{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} of the solar insolation at the top of the atmosphere and it is all claimed to be absorbed by the surface!  The greenhouse gases absorb a very unrealistic 90{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} of all of the radiation emitted from the surface!