tisdag 14 september 2010
Lindzen-Spencer: Confused Skepticism
After giving support to "backradiation" as the physics behind "global warming" Roy Spencer now follows up by giving praise to the basic idea of climate alarmism of a "greenhouse effect" capable of warming the Earth surface to 30 C, if it was not curbed by convective effects reducing it to 15 C, an idea also propagated by Richard Lindzen.
The idea is thus that a lapse rate of about 10 C connecting the Earth surface at 30 C to the top of the atmosphere TOA at -18 C (at the height of 5 km) is determined by radiation alone, which then by convection is reduced to the observed 6.5 C.
The Earth surface is thus supposed to radiate 390 W/m2 of which 240 is radiated to outer space from TOA and 150 are absorbed by the atmosphere and then "backradiated" to the Earth surface contributing to global warming.
I have questioned the physics of "backradiation" as non-existing, and I argued that the lapse rate is not primarily determined by radiation, but by thermodynamics, with radiative heat transfer from the Earth surface to TOA acting passively on the thermodynamic lapse rate.
In this setting there is no "backradiation": Out of the total incoming 180 W/m2 to the Earth surface, 120 is transferred to TOA by convection and 60 by radiation acting on a lapse rate of 6.5 C/km (with 60 absorbed by the atmosphere out of total 240).
It is strange to see leading climate scientists, appearing as skeptics to climate alarmism, still propagating basic misconceptions of climate alarmism such as a powerful "greenhouse effect"
based on radiation alone.
Cannot Lindzen and Spencer understand that the lapse rate primarily must be determined by thermodynamics and not radiation? Why buy the basic argument of climate alarmism,
without subjecting it to scientific scrutiny? Why not scientific skepticism instead of confusion?