From The Hockey Shtick, word of a new paper that supports Miskolczi’s theory of saturated greenhouse effect. We’ve seen this before, in the form of this graph.
In 2006, Willis Eschenbach posted this graph on Climate Audit showing the logarithmic net downward IR forcing effect of carbon dioxide relative to atmospheric concentration:
The flatter portion of the graph gradually smooths out, as the effect of CO2 forcing becomes saturated with increased concentration. And this graphic of his shows carbon dioxide’s contribution to the whole greenhouse effect:
What’s more, in this new paper there appears to be some evidence for a negative climate feedback, in the form of slightly lowered relative humidity trend, which makes climate sensitivity lower. Relative humidity (RH) is the ratio of the actual amount of water vapor in the air to the amount it could hold when saturated expressed as a percentage OR the ratio of the actual vapor pressure to the saturation vapor pressure expressed as a percentage. The amount of water vapor the air can hold increases with temperature. Relative humidity therefore decreases with increasing temperature if the actual amount of water vapor stays the same. While the study found a slight increase in specific humidity (the mass of water vapor per unit mass of air), relative humidity (near the surface, 2 meter measurement) decreased by 0.5% per decade, resulting in an overall slightly drier atmosphere.
If a positive water vapor feedback response existed in the climate system, you’d expect both the specific and relative humidity to increase with time. It didn’t. This ends up putting the kibosh on the idea of tipping points, and a lack of positive water vapor feedback pretty much takes all the scare out of CO2 induced climate change.
Of note is the issue with station inhomogeneity which apparently had been masking the signal in earlier studies. This study looked at stations individually to determining where such inhomogeneity existed. Here’s an example in figure 3 of their paper:
A paper published today in the Journal of Climate finds that relative humidity has been decreasing 0.5% per decade across North America during the 62 year period of observations from 1948-2010.
Computer models of AGW show positive feedback from water vapor by incorrectly assuming that relative humidity remains constant with warming while specific humidity increases. The Miskolczi theory of a ‘saturated greenhouse effect’ instead predicts relative humidity will decrease to offset an increase in specific humidity, as has just been demonstrated by observations in this paper. The consequence of the Miskolczi theory is that additions of ‘greenhouse gases’ such as CO2 to the atmosphere will not lead to an increase in the ‘greenhouse effect’ or increase in global temperature.
Journal of Climate 2012 ; e-View
V. Isaac and W. A. van Wijngaarden*
Physics Dept., Petrie Bldg., York University, 4700 Keele St., Toronto, ON Canada, M3J 1P3; e-mail: email@example.com
Over 1/4 billion hourly values of temperature and relative humidity observed at 309 stations located across North America during 1948-2010 were studied. The water vapor pressure was determined and seasonal averages were computed. Data were first examined for inhomogeneities using a statistical test to determine whether the data was fit better to a straight line or a straight line plus an abrupt step which may arise from changes in instruments and/or procedure. Trends were then found for data not having discontinuities. Statistically significant warming trends affecting the Midwestern U.S., Canadian prairies and the western Arctic are evident in winter and to a lesser extent in spring while statistically significant increases in water vapor pressure occur primarily in summer for some stations in the eastern half of the U.S. The temperature (water vapor pressure) trends averaged over all stations were 0.30 (0.07), 0.24 (0.06), 0.13 (0.11), 0.11 (0.07) C/decade (hPa/decade) in the winter, spring, summer and autumn seasons, respectively. The averages of these seasonal trends are 0.20 C/decade and 0.07 hPa/decade which correspond to a specific humidity increase of 0.04 g/kg per decade and a relative humidity reduction of 0.5%/decade.
The full paper from the Journal of Climate can be viewed at this link.