Guest post by David Middleton
Featured image borrowed from ExxonKnew
In my previous post on this subject, we examined some of the documents which supposedly proved that ExxonMobil and the oil industry in general “had the underlying knowledge of climate change even 60 years ago.” This is funny for at least two reasons:
- Oil companies employ a lot of sedimentary geologists and two of the primary components of sedimentary geology are 1) paleogeography and 2) paleoclimatology. So the oil industry has “had the underlying knowledge of climate change” for a very long time.
- ExxonMobil’s (Humble Oil back then) underlying knowledge of climate change was that “the theory that climatic variations are effected by variations in the CO2 content [was becoming] very questionable.”
One of the most damning documents was the 1968 Robinson Report for the American Petroleum Institute (API).
In 1968, scientists with the Stanford Research Institute reported to the American Petroleum Institute about their research on atmospheric pollutants of interest to the industry. Summarizing the available science, the scientists saved their starkest warnings for carbon dioxide (CO2). They cautioned that rising levels of CO2 would likely result in rising global temperatures and warned that, if temperatures increased significantly, the result could be melting ice caps, rising sea levels, warming oceans, and serious environmental damage on a global scale.
One of the reproduced pages from this damning report referenced Möller (1963) as the source of a 1-7 °F rise in temperature due to a 25% rise in atmospheric CO2…
The numerical value of a temperature change under the influence of a CO2 change as calculated by Plass is valid only for a dry atmosphere. Overlapping of the absorption bands of CO2 and H2O in the range around 15 μ essentially diminishes the temperature changes. New calculations give ΔT = + 1.5° when the CO2 content increases from 300 to 600 ppm. Cloudiness diminishes the radiation effects but not the temperature changes because under cloudy skies larger temperature changes are needed in order to compensate for an equal change in the downward long-wave radiation. The increase in the water vapor content of the atmosphere with rising temperature causes a self-amplification effect which results in almost arbitrary temperature changes, e.g. for constant relative humidity ΔT = +10° in the above mentioned case. It is shown, however, that the changed radiation conditions are not necessarily compensated for by a temperature change. The effect of an increase in CO2 from 300 to 330 ppm can be compensated for completely by a change in the water vapor content of 3 per cent or by a change in the cloudiness of 1 per cent of its value without the occurrence of temperature changes at all. Thus the theory that climatic variations are effected by variations in the CO2 content becomes very questionable.
Thus the theory that climatic variations are effected by variations in the CO2 content becomes very questionable.
This was priceless!!! So I spent $6 to rent the paper for 48 hours. Here are some highlights:
In this case, we must distinguish between the assumptions that the water vapor content (in cm l.e.) remains unchanged in spite of heating (cooling) of the atmosphere and that it increases (decreases). Constant absolute humidity means that the relative humidity (f) decreases from 75 to 70.34 per cent with a 1° or lowered by 4.66 per cent per deg. According to the above-mentioned calculations, an increase in CO2 from 300 to 600 ppm gives us a temperature change ΔT = +1.5° for Δf = -4.66 per cent per deg, and a temperature change ΔT = +9.6° for Δf = 0.
We recognize that for Δf = 0.8 per cent per deg the temperature change becomes infinite. Very small variations effect a reversal of sign or huge amplifications.
It is not too difficult to infer from these numbers that the variation in the radiation budget from a changed CO2 concentration can be compensated for completely without any variation in the surface temperature when the cloudiness is increased by +0.006 or the water vapor content is decreased by -0.07 cm l.e.
These are variations in the cloudiness by 1 per cent of its value or in the water vapor content by 3 per cent of its value. No meteorologist or climatologist would dare to determine the mean cloudiness or mean water content of the atmosphere with such accuracy; much less can a change of this order of magnitude be proved or its existence denied. Because of these values the entire theory of climatic changes by CO2 variations is becoming questionable.
So, way back in 1963, the entire oil industry knew exactly what we know today:
The entire theory of climatic changes by CO2 variations is questionable.
Oddly enough, both water vapor content and relative humidity have declined over recent decades. If I cross plot relative humidity (RH) at 600 mb against HadCRUT4 I get a Δf = -4.72 percent per degree C. This yields a climate sensitivity of about 1.4 °C per doubling of CO2 concentration.
Möller, F. (1963), On the influence of changes in the CO2 concentration in air on the radiation balance of the Earth’s surface and on the climate, J. Geophys. Res., 68(13), 3877–3886, doi:10.1029/JZ068i013p03877.