tisdag 27 april 2010

Summary: Incorrect Postulate of Climate Science

In a series of posts on climate sensitivity I have been searching for the scientific basis of 
alarmism of global warming from atmospheric CO2.  If there is a rational scientific basis, it is well hidden without any references. 

What I have found is an irrational non-scientific basis, which can be summarized in the relation dQ = 4 dT connecting "radiative forcing" dQ to "global warming" dT, which is the Basic Postulate of global warming alarmism.

The Basic Postulate comes trivially from differentiating Stefan-Boltzmann's Black Body Radiation Law Q= c T^4 at T = 273 K with Q = 273 W/m^2, as shown in previous posts.

That this is the derivation of the Basic Postulate is evidenced in the basic document of climate alarmism  Carbon Dioxide and Climate A Scientific Assessment by the National Academy of Sciences:
  • For the simplest case in which only the temperature change is considered (no feed back), and the Earth is assumed effectively to be a black body the value of dQ/dT = 4 cT^3 is readily computed to be about 4 W/m^2. For such a case doubled CO2 produces a temperature increase of 1 C.
Climate alarmism was then presented as a direct corollary to the Basic Postulate, with a bit of ad hoc feed back:
  • Our best estimate is that changes in global temperature of the order of 3 C will occur and that these will accompanied by significant changes in regional climate patterns.

The relation dQ = 4 dT can be used to compute "radiative forcing" dQ= 2.8 W/m^2  attributed
to increased CO2 during the 20th century from an observed dT = 0.7 K.  A projection into 
this century can then give dT = 1.4 K from a double dose of "radiative forcing" from doubled CO2, which with a dose of feed back can give the desired alarming 3 C. Clever or stupid?

The scientific basis of IPCC global warming alarmism is thus Stefan-Boltzmann's Radiation Law as a model of global climate, coupled with an attribution of some warming during the 20th century entirely to CO2. 

But Stefan-Boltzmann's Radiation Law is not a model of global climate, because the Earth with atmosphere dynamics does not function like a black body.  The relation dQ = 4 dT cannot be used to draw any conclusions about neither dQ nor dT. Nor can temperature variations arbitrarily be attributed to CO2. 

The Basic Postulate dQ = 4 dT of IPCC global warming alarmism thus lacks scientific basis. 

How is it possible that Royal Academies of Sciences continue to support a global warming alarmism which does not have any scientific basis?

The comments below lead to the following strategy to come to grips with a climate alarmism
without any scientific basis:
  • In any debate, just repeat  one question: WHY is dQ = 4 dT?
  • When repeated 10-100 times without any answer, the debate is over. Try it!
PS The documents lead back to the 1981 Science article Climate Impact of Increasing Atmospheric Carbon Dioxide, by James Hansen, et al, where it is claimed that:
  • The estimated black body Earth surface temperature without atmosphere is 255 K.
  • The 33 K increase  to the observed 288 K is the greenhouse effect of gases and clouds. 
  • The surface greenhouse effect is analogous to the depth of water in a leaky bucket with constant inflow rate. If the holes in the bucket are reduced in size the water depth and pressure will increase until the flow rate of of the holes again equals the inflow rate.
This is the scientific basis of global warming alarmism, basically the same as dQ = 4 dT, resting on Stefan-Boltzmann's Radiation Law and the obviously incorrect assumption that the Earth surface temperature is determined by radiation only, without major influence from convection evaporation/condensation. Is it reasonable to base far-reaching regulations on this form of black magic science? From a very leaky bucket of science? DS

PS 2 There is something correct about the leaky bucket analogy, which has been forgotten by followers of Hansen, namely that the inflow rate is constant, that is that there is no "radiative forcing" from greenhouse gases.

4 kommentarer:

  1. I guess that pride and willful ignorance makes people stick to this theory. They have spent so much time and energy on it that they just cannot grasp that they have been wrong for all these years. It's called denial. Funny how the people who are in denial are the ones who coined the expression "denialists"....

    I'm afraid that we will hear about CO2 for many decades to come, religion is hard to quench once it got it's roots into the fertile soil of ignorance.

  2. Maybe, but since it is so clear that the basic postulate lacks scientific basis, I think that any debate on global warming can be killed by simply repeating this fact.

  3. Proponents of most belief systems are prone to ignoring facts that contradicts their world view. I wish facts were an issue in the climate debate, it might be in the (near) future but right now there are still alot of talk about "consensus" as if that is how science works.

  4. I think it is a question of argument efficiency: If you can pin down the
    basic question to the validity of dQ = 4 dT, then there is a chance that the argument can bite. Just ask repeatedly WHY dQ = 4 dT? I think scientific
    debates are resolved by exhaustion through perseverance...