Saturday, November 29, 2014

The Greenhouse Equation predicts 1% change in cloud cover changes global temperature by 1°C

The albedo terms in the greenhouse equation can be used to determine the effect of an increase or decrease of cloud cover upon the global temperature, and finds a 1% change up or down in cloud cover/albedo produces a 1°C temperature change at the surface. This indicates the Earth temperature is quite sensitive to swings in global cloud cover or other albedo sources, such as the well-known global dimming that produced the ice-age scare of the 1970's, which was followed by global brightening since, and which is likely responsible for much of the warming since the 1970's.

Climate models are unable to skillfully model clouds and thus albedo, and use a rough assumption of a 30% global average albedo. If we decrease albedo by 1% from 0.30 to 0.29, the greenhouse equation predicts an increase in surface temperature from 288.433°K to 289.457°K, an increase of 1.024°C warming, mathematically verifying what Dr. Roy Spencer writes in his book
"The most obvious way for warming to be caused naturally is for small, natural fluctuations in the circulation patterns of the atmosphere and ocean to result in a 1% or 2% decrease in global cloud cover. Clouds are the Earth’s sunshade, and if cloud cover changes for any reason, you have global warming — or global cooling."
The 2 albedo terms in the equation are notated

1 comment:

  1. And this is how the sun causes cloudiness changes:

    with this describing the practical consequernces in climate terms: