Wednesday, November 23, 2011

False assumption of black-body earth surface leading to false illusion of global warming

The false assumption that the earth surface is a black body surface has been identified being a fatal technical error leading to false illusion of global warming.

The Stefan-Boltzmann law states that a black-body object with surface temperature, T, emits energy σT4 per unit time and unit surface area, where σ is the Stefan-Boltzmann constant equal to 5.670373 x 10-8 (W/m2K4).  For an object with any surface, it emits ε σT4, where ε is surface emissivity of the object.  ε is a value between 0 and 1; 0 is literally for white and transparent bodies, and 1 for black bodies.  Most substances are grey bodies with 0 < ε < 1. 

When the Stefan-Boltzmann law is applied to calculate the Earth’s outgoing emission flux, Qe, one shall write:
     Q=  4prε  σT4
where, r, is radius of the Earth,  and T is the Earth’s mean surface temperature; 4pr2 constitutes of the surface area of the Earth.
In current climate research, ε is either missing in the expression or asserted to be unit.  By taking ε = 1, one has assumed the earth surface a black-body surface, which means that almost everything on the earth surface ¾ ocean, soil, snow and vegetations etc are all objects with black-body surface!  Truly this is illogically wrong. 

For a given outgoing flux, Qe, the calculated mean earth surface temperature T for ε = 1.0 becomes lower than that for ε < 1.0.    

This technical error has led to a widely spreading misunderstanding that the Earth would be much colder should there is no greenhouse gas effect.  With ε = 1.0, one obtains T = -18°C, which is then compared with actual mean near surface air temperature 15°C.  The difference 33°C has been considered a common measure of the greenhouse effect [e.g. Lucis et al. “Atmospheric CO2: Principal Control Knob Governing Earth’s Temperature” Science 33, 356-359 (2010)].

Numerous documents have made similar statements without realising the value of -18°C is incorrect.  The Joint Science Academies’ Statement: Global Response to Climate Change (2005) by academies of Brazil, Canada, China, France, Germany, India, Italy, Japan, Russia, UK and USA stated:
“The existence of greenhouse gases in the atmosphere is vital to life on Earth – in their absence average temperatures would be about 30 centigrade degrees lower than they are today.”
CSIRO’s Science and Solutions for Australia – Climate Change (2010) writes:
“The surface of the planet would be more than 30°C cooler than it is now without this natural greenhouse effect, and life as we know it would not be possible.”
After quoting the Science paper, the Australian Climate Commission Report – The Critical Decade (2011) continues:
“In fact, without these long-lived greenhouse gases, the Earth’s temperature would drop rapidly and drive the planet into an ice-bound state.”

It is a collective error in current climate research.  One can find the error in peer reviewed academic publications as well as in climate science textbooks.  It may prove to be the most expensive technical error we ever had in the human history.  (By Dr. J. Cao, Australia)

Sunday, November 20, 2011

Physical analysis shows CO2 is a coolant for the atmosphere

There is a fallacy dominating the way of our thinking in current climate research that radiative gases such as carbon dioxide and water vapour are regarded greenhouse gases that trap heat and warm up the atmosphere.  Physics analysis of carbon dioxide, oxygen and nitrogen molecules, however, tells a different story: carbon dioxide is cooler than, gains heat by molecular collision from, and dissipates heat by radiation for nitrogen and oxygen.  Indeed, CO2 is a coolant of the atmosphere, and it is nitrogen and oxygen gases that award the Earth a warm liveable near surface atmosphere. 

The physical principle behind the analysis lies in the Kirchhoff’s law of 19th century radiation physics, which can be restated in plain English as: an object that absorbs emits and an object that emits absorbs.   Absorption and emission are two inseparable equivalent identities of the same physical essence.  Carbon dioxide absorbs infrared therefore it emits as well thermal radiation.  Nitrogen and oxygen do not absorb, therefore do not emit.  CO2 approaches 0 K because of its emission if there is no radiation source; absorption of the thermal radiation from the earth ground surface rises CO2 temperature from -273.15°C to -78°C only.  CO2 gains heat by colliding with warmer nitrogen and oxygen to rise its temperature further, which can be measured by spectroscopy.   

We will have a better understanding of the physical principle if one notices that a computer case is often designed black.  This is because a black surface emits more heat out so the computer will be cooler.  On the other hand, an industrial boiler is usually painted silver to reduce thermal emission to reserve heat. 

With this alternative interpretation, we have a better explanation of the temperature-altitude profile of the atmosphere; in particular, a better explanation of the existence of the thermosphere where the molecular temperature of residual oxygen gas is well above 100°C ¾ CO2 gas is sorted out in the thermosphere due to its heavier molecular weight. 

A PDF file of the full manuscript entitled “Role of heat reservation of N2 and O2 and the role of heat dissipation of CO2 and water vapour” is available to download if interested.

(By Dr. J. Cao, Australia)