EIKE Institute: “Anthropogenic Greenhouse Effect Too Weak…Doubling CO2 Will Lead Only To 0.58°C Warming”

What temperature rise does a doubling of atmospheric CO2 lead to? Overall, the IPCC says anywhere from about 2 – 6°C, i.e. they don’t know.

Recently the Germany-based European Institute for Climate and Energy (EIKE) posted an essay by Dr. Wolfgang Burkel, who concludes that doubling atmospheric CO2 will lead only to a 0.58°C of warming at the Earth’s surface.

What follows is a translation and summary of his essay.

Dr. Burkel’s calculation method looks at the energy balance directly at the Earth’s surface. Evaporative cooling of additional water vapor is so powerful that only 0.58°C of warming is enough for compensating a doubling of CO2 concentration.


Anthropogeníc Greenhouse Effect Too Weak For A Climate Catastrophe!
By Wolfgang Burkel

The greenhouse effect of CO2 is expressed by the formula: dF = 5.75ln(C/Co).

Figure 1: Logarithmic climate sensitivity of CO2.

Figure 1 shows that a doubling of CO2 concentration delivers an additional radiative forcing of 3.7 W/m², which in turn leads to an atmospheric warming of about 1°C, which is accepted by almost all scientists. The IPCC provides a figure of 1.2°C; Lüdecke and Link [2] calculate 1.1°C. Other sources provide similar values.

The problems begin when the results are carried over to the Earth’s surface. Suddenly the values diverge immensely. Even within the IPCC itself there is no agreement. See the following chart:

Figure 2: CO2 effect according to the IPCC AR4 2007.

First of all one sees that the values in the table appear as guesses, and are thus alien to any scientific method. The reason for this are the varying estimates of ‘positive feedbacks’, which are built into the politically dominated models. But logic does not support a positive feedback. How should a small warming of the atmosphere lead to a large warming at the Earth’s surface?

Why does one calculate a change in global temperature by taking a detour through the atmosphere? The result is useless because there is no consensus on what it means for the Earth’s surface.

Figure 3: Energy budget at the Earth’s surface and change through the greenhouse effect (in parentheses): Evaporation 84 W/m² (+4); Radiation 45 W/m² (-4) and convection 17 W/m² (+0). Absorbed from the sun 140 W/m² (+/- 0). Earth’s surface temperature: 15°C (+0.58°C).

Figure 3 shows the heat flux as part of the energy budget. What happens in the atmosphere or at the outer edge is insignificant for the energy balance. The energy at the Earth’s surface eventually finds its way out into outer space.

There’s a consensus on the magnitudes of the energy flux: evaporation is 84 W/m², radiation is 45 W/m² and convection is 17 W/m². A change in one is compensated by the others. Anthropogenic greenhouse effect reduces the energy flux from radiation. But then the temperature of the Earth’s surface rises until a new equilibrium gets established.

For calculating the warming, the dependence of the three above-mentioned transport mechanisms on temperature is used.


Evaporation of water removes heat from the Earth’s surface and transports it to the upper atmosphere, where it gets dumped as the vapor condenses. For the stability of the climate, this is of great importance because the evaporation heat is strongly dependent on the Earth’s surface temperature. With an average of 84 W/m², evaporation provides almost 60% of the heat transport from the Earth’s surface towards the upper atmosphere. We know that precipitation on Earth has increased over the last 100 years, and thus transports more heat back to the upper atmosphere, away from the Earth’s surface.

A warming of 1°C increases heat transport due to evaporation back to the upper atmosphere by 7.5%. At 84 W/m², that translates to 6.3 W/m² of additional cooling effect for the Earth’s surface. As we see, evaporation acts as a powerful brake against changes in climate.


About 70% of the long-wave radiation from the Earth’s surface is absorbed by the greenhouse gases. Direct radiation from the Earth’s surface into space is about 45 W/m². This value is reduced somewhat by the higher anthropogenic greenhouse effect. A doubling of atmospheric CO2 concentration results in a radiation reduction of 4 W/m² (as mentioned earlier).

But radiation intensity is proportional to the 4th power of the absolute temperature. A warming of 1°C translates to 1.4%, or 0.63W/m².

There’s also a feedback from additional water vapour in the air. Using Figure 5 below, water vapor at its current concentration delivers a maximum 8 W/m² of radiative forcing.

Figure 5:  The effect of greenhouse gases on thermal radiiation.

And with 7.5% more water vapor, this yields an additional radiative forcing of 0.6 W/m². Note that Figure 5 shows that effect of various greenhouse gases greatly depends on the spectrum wavelength.

Figure 5 shows that the effect of CO2 as a greenhouse gas is limited to a narrow long-wave range in the neighborhood of 14 microns, and is for the most part saturated.

Also additional water vapor has only a marginal impact.


As the Earth’s surface temperature rises, warm air travels up and transports heat to the upper atmosphere. Convection provides only about 12% of this outward heat transfer, and thus we will neglect it here.

Tallying it all up

Summary of changes in energy flux resulting from 1°C of warming:

Evaporation: +7.5% = 6.3 W/m²
Convection: (negligible)
Radiation: +1.4% = 0.63 W/m²
Feedback through water vapor: 0.6 W/m²

A warming of 1°C of results in an additional cooling effect of a total of 6.33W/m² because of mechanisms that transport heat away from the Earth’s surface and towards the upper atmosphere.

And we already know that doubling the atmospheric CO2 concentration leads to a radiative forcing of only 3.7 W/m², see Figure 6:

Figure 6: Warming as a function of CO2 concentration. Doubling CO2 concentration leads to a radiative warming of 3.7W/m². A 1°C warming leads to a tarnsport mechansim effect of 6.3W/m².

Using Figure 6, the exact value for climate warming is 0.58°C.

How does this figure compare to the current discussion? This figure is in agreement with Lindzen and Choi of MIT [3]. These two scientists quantified the climate sensitivity at 0.5°C using satellite data, i.e. real observations and not dubious computer simulations.

Hermann Harde [4] found a climate sensitivity of 0.62°C using spectroscopic examinations and model calculations.


The minimal effect of CO2 on climate is not surprising. This is confirmed by both theory and by actual observations and measurements.


7 thoughts on “EIKE Institute: “Anthropogenic Greenhouse Effect Too Weak…Doubling CO2 Will Lead Only To 0.58°C Warming””

  1. “Radiation

    About 70% of the long-wave radiation from the Earth’s surface is absorbed by the greenhouse gases.”

    The authors seem to ignore that in Local Thermal Equilibrium, absorption and re-emission on the same frequency happen with equal frequency.

    ” Direct radiation from the Earth’s surface into space is about 45 W/m². This value is reduced somewhat by the higher anthropogenic greenhouse effect. A doubling of atmospheric CO2 concentration results in a radiation reduction of 4 W/m² (as mentioned earlier).”

    I doubt that. The density of a greenhouse gas in local thermal equilibrium does not change the fact that absorption and emission happen with equal frequency; only the mean path length between absorption and re-emission is affected.

    “But radiation intensity is proportional to the 4th power of the absolute temperature. A warming of 1°C translates to 1.4%, or 0.63W/m².”

    Let’s not conflate aborption/emission characteristics of blackbodies/greybodies and gases. Water vapor is a gas; water droplets act like a blackbody for IR photons. The Stefan-Boltzmann law is the one that contains the 4th power of abs. temp. but is only valid for blackbodies/greybodies.

    So, at the surface, which acts as a greybody, a higher temperature WILL lead to more emission; same for water droplets (assuming that water droplets in clouds also get warmer), but greenhouse GASES are not affected by temperature; they emit/absorb the same line spectrum at every temperature, not a blackbody spectrum which is continuous and depends on the temperature.

    In my opinion the authors are right about increased evaporation (if there is warming) but I’m with Ed Caryl and MODTRAN about the next to non-existant increase in backradiation from greenhouse gases.

    1. I’m also wondering what Ed will say about it. I find the water vapor part of it interesting. Indeed it is a huge conveyor for transporting heat away from the surface (negative feedback and not only a GHG (positive feedback).

    2. I have been using “frequency” in two different ways:
      “on the same frequency happen with equal frequency.”

      It’s clearer when I say:
      “Absorption and re-emission happen on the same wavelength with equal frequency.”

      Sorry if it confused anyone.

  2. I see no mention of clouds – albedo changes. That can’t be left out. I view their figure as an upper bound. Others, including Roy Spencer, John Christy, Willis Eschenbach, among others, have deduced that same 0.6 degree figure. I think it still might be too high.

  3. Everyone who promulgates the “greenhouse effect” of increasing atmospheric temperature with increasing atmospheric carbon dioxide (CO2) invariably reverts to the authority of radiative transfer models, instead of confronting the definitive and clear evidence, of the comparison of temperatures in the atmospheres of Earth (with 0.04% CO2) and Venus (with 96.5%, some 11.36 doublings of Earth’s atmospheric CO2 concentration). None of them show basic competence, in ignoring that definitive evidence (and they SHOULD KNOW IT, as professional scientists writing on this subject, since the Venus data is 20 years old, and the Earth Standard Atmosphere, over a century).

    Go to Venus: No Greenhouse Effect, and look at the Venus/Earth data presented there, particularly the graph of temperature vs. pressure for the two planets, when Venus’s curve is corrected solely for its smaller distance from the Sun. The two curves are right on top of each other, above and below the Venus cloud layer. If there were a CO2 temperature effect of even 0.58 degrees C/doubling, the Venus curve should be over 6 degrees higher than Earth’s T-P curve — AND IT IS
    NOT! From the Venus/Earth data, I have calculated that the CO2 temperature effect — the supposed “CO2 climate sensitivity” — is -0.03 +/- 0.1 °C per doubling of CO2. That is essentially zero, and should be reported as zero. That is the hard fact, that every academic and institutional climate scientist and atmospheric scientist MUST confront, and finally ACCEPT. The obvious truth demands no less.

    The hard truth is this: The radiative transfer theory, as applied to warming in the atmosphere, does not agree with the Venus/Earth comparison, and is therefore WRONG. Period. The sooner honest and competent scientists begin to acknowledge this, the sooner climate science can be corrected, and actual progress made in that field — not before.

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