As the direct warming effect of CO2 greenhouse effect is rather marginal, (arguably beween 0.1 and 1.0 degrees C per doubling CO2), we invented the famous positive feedback, notably caused by the much stronger greenhouse effect of water vapor, snow albedo, and what not, to get it to the IPCC ~3 degrees per doubling CO2.

It's almost over

positive feedback, have we been fooling ourselves? (http://climatesci.colorado.edu/2007/08/14/positive-feedback-have-we-been-fooling-ourselves-by-roy-spencer/)

The traditional way in which feedbacks have been diagnosed from observational data has very likely misled us about the existence of positive feedbacks in the climate system.

Our new analyses of satellite observations of intraseasonal oscillations suggest negative cloud feedbacks, supporting Lindzen’s Infrared Iris hypothesis.

I am increasingly convinced that understanding precipitation systems is the key to understanding climate sensitivity.

But then again, no positive feedback, we knew that already for years:

http://www.aai.ee/~olavi/2001JD002024u.pdf

Not much science left for anthropogenic global warming

Hello Andre, et al.

Have you read this information http://physics.nist.gov/Divisions/Div844/facilities/isam/isam.html

There are other ways for IR radiation to be absorbed than just CO2, CH4, etc.

:)

Not much science left for anthropogenic global warming So I'm not following the argument - are positive feedbacks impossible, countered by other effects (such as clouds), not involved in the observed warming, not large enought to worry about regardless of its distribution, what?

IIRC earlier you were arguing that CO2 absorption of infrared did not warm the atmosphere. Now it's just not enough warming to worry about. And apparently it's not enough to worry about because other effects are guaranteed to counter any positive feedbacks, regardless of the distribution of the warming effects and regardless of the feedback effect involved.

The source of your guarantee is what, exactly - observations of no disaster so far?

btw: IIRC the variability correlation your second link reports ended about 2001, and the apparent negative feedback hypothesized by the discoverers of that 20 year statistical correlation (whatever it was presumed to have been) no longer appears in the data.

Also, the satellite data that analysis was based on has been corrected, since 2001, and the analysis itself needs reworking.

In particular, its presumption of there being no historical planetary scale climate information - both irradiance and temperature - available for places not covered by weather stations many years ago is dubious - to put it mildly.

Most positive feed backs usually have negative consequences!

When ice melts over the ocean, the seawater then absorbs more sunlight and heats up, thus melting more ice. This is the positive feedback that is happening now. Andre doesn't know what he's talking about.

Hello all

We all know that temperature falls as we gain altitude. The question I have is how much altitude would be required to offset a change in temperature if CO2 was doubled.

For some information see here http://edweb.sdsu.edu/wip/examples/temps/

This all relates to an idea that increasing levels of CO2 change the rate at which the temperature falls off with altitude. Higher altitude temperature measurements are affected more that lower altitude measurements because of air pressure. If this theory hold true then you cannot lump sum averages at different elevations or barometric pressures over time without skewing the result.

The correct way would be to only sum the data for a limited range of barometric pressures. Then graph each range as a function of time to see what CO2 does for each pressure range over time.

You cant say there is global warming if the livable zone within the atmosphere is just expanding in altitude because of CO2 increases. Or can you. There would be little effect at sea level but a large affect at altitude.

:)