Could someone please show me a pro AGW scientific report?

Question

Specifically, I would like to see any pro AGW reports which deal with water vapor (the primary global warming agent), the decreasing ability of CO2 to warm as more is added to the system, and the effect of clouds to the global warming system.

I think if some of these issues were addressed in a scientific report, many sceptics would consider the theory plausible. For me, I find it impossible to believe in the theory when every article completely dismisses (or minimizes) these important issues. Also, a good explanation of why positive feedback is used by AGW fanatics instead of the most naturally occuring negative feedback. And PLEASE, do not refer to the "consensus" as scientific proof.

Pantagruel - Why are you wasting my time with your silly comment. Please come back with some scientific evidence please.

Trevor - I have skimmed the IPCC reports. I will read them more closely. Cna you point me to the sections which contain the issues I asked about? As for the positive feedbacks, AGW fanatics like to have water vapor be a positive feedback to the system. This allows them to magnify their estimates 2 to 4 times the anticipated CO2 increase. However, when they do this, they never address the issue of cloud formation into the mix as it is a negative feedback. And, in nature, I have never seen a positive feedback, except a nuclear bomb. So why do AGW fanatics always use positive feedbacks, even though they are VERY rare, and, they apparently did not occur in previous warmer climates?

Grizzbr1 - Put your money where your mouth is. If you scientific evidence about my issues, please post them. Otherwise stop wasting everyones time with your useless banter.

Answer 1

You should take your false assumtions and move to Atlanta to open a waterslide park.

Answer 2

I'm going to guess you are talking about Lindzen's "Iris hypothesis" or some variant on it, where deep convection of water vapor acts as a negative feedback, cooling the planet. There was an article by Fu et al. that appears in the journal Atmospheric Chemistry and Physics in 2002 (see reference below). It points out that in Lindzen's original paper on the Iris hypothesis, Lindzen made some unrealistic assumptions which made the Iris effect larger than it probably is. There was a good deal of back and forth between the two groups, however on balance it was generally agreed that Lindzen lost the discussion.

More recently, in August of 2007, Roy Spencer and co-workers published a study in Geophys. Res. Letters providing some evidence for the Iris effect, or more accurately, something related to the Iris effect. However, Spencer analyzed a very partial set of available satellite data, basically selecting 5 years (out of a 20 year record) that suggested increased tropical clouds and deep convection were cooling on average (although the correlation isn't all that great). There hasn't been enough time since the Spencer et al. paper for there to have been any detailed responses or verification using longer data records or other radiative transfer models.

Answer 3

All the points you mentioned, and a great deal more, are covered in detail in the varuous IPCC reports. You can access the assessment reports here... http://www.ipcc.ch/ipccreports/assessments-reports.htm

There's 000's of pages but the reports have indexes and chapter listings which will speed up the search for the info you're looking for.

Your points have been covered many times and are published in lots of different reports, if you do an online search you'll find many of them.

Can you elaborate on "a good explanation of why positive feedback is used by AGW fanatics instead of the most naturally occuring negative feedback" as I'm not sure what you're asking or referring to.

Answer 4

The analysis of the greenhouse seems to be divided into two steps.

1. Calculate the change in radiative forcing (the heating effect equivalent to increasing the radiation intensity incident on the earth).

2. Work out what warming that could cause.

The reason climatologists talk about positive feedback is they are only looking at radiative forcing, not total heating. Positive feedback in that when the earth is heated, the absolute humidity of the atmosphere increases and traps more heat. Net positive feedback on warming isn't plausible because as a body warms, the rate at which it rejects heat (in the form of radiation) increases exponentially.

Skeptics have been talking about negative feedback from clouds since I first started reading about the greenhouse effect about 15 years ago, but climatologists seem reluctant to incorporate this into their models.

Climatologists seem to work on the theory that for every Watt per sq metre of radiative forcing, the temperature of the earth will warm by 0.75 degrees. I haven't seen any discussion on how they come up with this number - but if you consider the earth as a black body radiator, I estimate the earth would only increase by 0.06 of a degree for every Watt per square metre increase in solar radiation. (radiation is proportional to temperature the power of 4, a 0.1% increase in radiation could cause a 0.02% increase in absolute temperature).

It seems a bit suspicious that the IPCC reports talk in very great detail about radiative forcing, but don't discuss the other 50% of the theory which is what effect this will have on warming. It could be a bit of smoke and mirrors here. Maybe the theory is somewhat speculative in this regard.

Answer 5

Crazy, I agree that the assumption of warmer temperatures will mean more water vapor and therefore be a positive feedback is not well established. It is well established that high level clouds cause warming and low level clouds cause cooling. But it is not clear to me that increased water vapor leads only to high level clouds. I do not know of any scientific paper that makes a compelling argument for this.

Also, galactic cosmic rays play a role in the creation of low-level clouds and that fact has to be considered.

In a general sense, it seems to me that warmer weather is dryer. If you consider to the dust bowl years of the 1930s, which I believe was definitely warmer than now, it was a much dryer climate. When there is a great deal of water vapor, I think it means more clouds and more rain and more cooling.

Also Roger Pielke has written that net feedbacks must be negative based on the IPCC's own data.
http://climatesci.colorado.edu/2007/03/19/climate-feedbacks-must-be-a-negative-effect-on-the-global-average-radiative-imbalance-if-the-ipcc-conclusion-of-anthropogenic-radiative-forcings-are-correct/