A paper published today in the Journal of Geophysical Research finds that a natural atmospheric oscillation, the Southern Annular Mode, is correlated to significant increases in cloud cover resulting in “large scale” local cooling of approximately -2.5C.
All climate models falsely assume clouds result in net positive feedback and increased temperatures, however this new paper and several others show clouds instead result in net negative feedback and cooling.
It becomes obvious that the ‘climate modellers’ who assume ‘clouds result in net positive feedback and increased temperatures’ are all city folk. Nobody who had ever stood out in the open as a summer cloud drifted across the sun could ever say anything so preposterous.
I think it’s pretty clear that they are not publishing proof that it’s cooler in the shade
Maybe someone can help me out – “Wasn’t ‘positive feedback’ the cornerstone of AGW theory?”
Now what?
And it remains the cornerstone, although it was never just about clouds. The hypothesis is that since warmer air can hold more water vapor then CO2-induced warming will lead to both warmer air (approx 1°C per 2xCO2) and increased evaporation to supply said increased water vapor. Water (in all its forms) is responsible for ~90% of net greenhouse effect and so more evaporation being held in the air increases greenhouse effect, increases air temperature, since warmer air can hold more water vapor… Rinse and repeat. Result being that the IPCC uses a marvelous magical multiplier of 2.5 and a base-case of 1.2°C, making 2xCO2 1.2×2.5 = 3°C for their median estimate.
The cloud thing is a little different in that there is a difference of opinion on whether a warmer atmosphere would lead to a greater increase in high, thin cloud or low, bright cloud because high, thin cloud is largely transparent to incoming solar radiation but opaque to outgoing earth radiation – low, bright cloud is highly reflective of incoming solar radiation and hence has an entirely different radiation profile. Thus the argument over whether increased cloud has a positive or negative effect – they’re talking different cloud mixes.
Hope that helps.
Ed.
There was an earlier paper on the so-called ‘Iris Effect’ on this subject of rising heat versus cloud response. As usual, because it did not support the PlayStation Climatology models, it was buried by the media clowns.
Think of a cloud as a big fat glob of rock wool insulation. When the heat source is the sun (daytime) the cloud acts to shade and protect the earth’s surface. That is why cloud cover on a July afternoon is welcome when you are picking up baled hay in an open field.
When the earth’s surface is the heat source (night time), cloud cover impedes the escape of heat radiation. Thus, in the third week of September, when you have night cloud cover, the tomato crop is protected from frost.
Pay attention. The evidence is all around you.