My sense is that most scientists consider the very high end of the sensitivity range (greater than 4°C) to be pretty unlikely (although it cannot be ruled out), and the most likely value for climate sensitivity is around, probably slightly below, 3°C.
In other words, I was not terribly worried about runaway climate change before this. After all, we know that the Earth’s had much higher CO2 in the past (and the temperature were correspondingly much higher), and the Earth did not turn into Venus.
So an increase of 170 ppm to 560 ppm would cause 3C increase in temperature. That implies 1.7C increase per 100 ppm. During the Jurassic, CO2 levels were as much as 2,000 ppm higher than at the present. Temperatures must have been more than 30C higher back then – using Aggie math.
On the other hand, during the Ordovician, CO2 levels were 4,000 ppm higher and we had an ice age. So we can say with 97% certainty that these experts have absolutely no clue WTF they are talking about.
h/t to suyts
Certainly rules out a linear relationship between atmospheric CO2 and temperature.
We are well past the knee of the logarithmic CO2 curve, so it should be close to linear now. The problem is that they have wildly exaggerated the magnitude of the slope.
It’s not linear, it’s zigzag logarithmic. Not a random walk, but a drunkards walk.
That explains everything.
It’s a travesty that we cannot show where that water went.
The United States Government has been dehydrating the water and storing it in a cave outside of Boulder Colorado. They figured they best place to hide the water was right under Trenberth’s nose. I also heard they have found a way to freeze dry warmth and they are hiding that from Trenberth in the same caves. Bush started it and Obambi’s group can not figure out how to stop the process of dehydrating water and freeze drying warmth!
When the rest of the world is suffering from drought and freezing we will be able to export warmth and water at a premium. That will teach them to say bad things about the US!
My favorite part, “and the Earth did not turn into Venus.”
Well, that’s a lot like what we’ve been saying all along. There’s nothing to worry about. CO2 won’t cause a thermageddon. Even a clueless Aggie knows this.
I wonder how Dessler figured that one out?
Probably from this.
He has prolly been reading Steve’s blog……
Whilst the atmosphere demonstrates a spectral absorption in IR, attributed to “greenhouse” gases (most likely water vapour), the atmosphere is open to the cold blackness of space, and radiates the excess.
This is why the climate “sensitivity” to CO2 is essentially zero – both from observational evidence of a lack of correlation between temperatures, and comparative planetology:
comparing Earth and Venus gives no indication of a “greenhouse” effect of higher CO2 is the atmosphere of Venus:
http://theendofthemystery.blogspot.com/2010/11/venus-no-greenhouse-effect.html
A similar comparision with Earth and Mars also shows that, at similar atmospheric pressure, the difference is temperature is solely due to distance from the Sun.
Doubters are challenged to find flaws with this argument.