Are there any scientific arguments against the man-made global warming theory?

Well I think there certainly are, but we don't usually see them on here. There are many questions left to answer about water vapor and cloud feedbacks in a warming atmosphere. I think Trenberth and Fasullo offer some hope for Lindzen's iris hypothesis in their recent GRL paper. Climate models are certainly imperfect, and as long as they rely on parameterizations of sub-grid scale processes they can be questioned.

I think the evidence is clearly on the side of AGW, but there are certainly arguments to be made on the other side. I never see anyone here that offers any informed criticism, though.

You'd think that somebody that claimed to have two doctorates would be able to, but alas nothing informed comes from that guy either.

EDIT: Bill C, that analysis doesn't really work, it only tells about the most extreme temperatures. If you look at the daily extreme temperatures (not the statewide ones), there is clearly a shift toward more warm extremes and fewer cold extremes, see the IPCC report

http://ipcc-wg1.ucar.edu/wg1/wg1-report.html

The lack of new statewide annual extremes could be connected with dimming due to aerosols.

EDIT for DaveH: Just which of the states are in the southern hemisphere?

I like to ask a question: These scientists & organizations that claim that it is man-made, who is funding their studies? It's a common misconception that scientists are unbiased. If that's the case, then ALL of the scientists in Nazi Germany should have fled from their country. My point is most "scientists" have agendas and commitments, just like the rest of us. They're human, like you and me. I'm not a scientist, but consider this: Volcanos emit more toxins and polutants into the air than say an oil refinery or nuke station. Consider the fact there are sunspots and solar flares and YES, they affect the Earth. Don't forget the levels of cosmic radiation that bombard are planet as well. And before man ever became advanced, here's something to consider, there have been ice ages, mass extictions, shifts of poles, etc. In essence, I am saying the Earth's not going anywhere -- we are! Pack your bags, because our time here is very limited. You can either make things better for your follow human or worry about something you have no control over.

For Dave M, here is the link you need. From NASA itself.

HISTORY

"The basic GISS temperature analysis scheme was defined in the late 1970s by James Hansen when a method of estimating global temperature change was needed for comparison with one-dimensional global climate models. Prior temperature analyses, most notably those of Murray Mitchell, covered only 20-90°N latitudes. Our rationale was that the number of Southern Hemisphere stations was sufficient for a meaningful estimate of global temperature change, because temperature anomalies and trends are highly correlated over substantial geographical distances. Our first published results (Hansen et al. 1981) showed that, contrary to impressions from northern latitudes, global cooling after 1940 was small, and there was net global warming of about 0.4°C between the 1880s and 1970s."

http://data.giss.nasa.gov/gistemp/

Since it warmed 0.4 C by the 1970's, we have warmed by a total of 0.6C- 0.7 C, then basic math says it has warmed by 0.2C-0.3 C since the 70s, not 0.5 C. But, all of that Hansen material is a "reconstruction" of past temperatures.

No offense Dana, but where is the proof that the #1 green house gas is not the driving factor? So far no scientist has come out and explained the effects of water vapor on climate change especially since water vapor makes up a grand total of 95% of all green house gases and only 1% of the 95% is man made. Also from my understanding all the charts and statistics show that CO2, methane, and other green house gases lag behind temperature change not drive it.

Can the man made crowd come up with any proof that doesn't ignore past climate history, doesn't use computer models that dumb down the Earth into one variable or few variables causing climate change? Finally, how does the fact that man's total contribution to green house gases is at most 3% driving the climate change off of a cliff?

For the person bringing up peer reviewed articles again, all that means is that people agree with your work, not that it is accurate or good science. There is a big difference and the scientific community has gone away from doing real research into doing research that brings in the most money. I have family that are into scientific research.

1) I am unaware of any published scientific data where a scientist says s/he has scientific data that PROVES that MGW is valid and a crisis. The IPCC never says so, and couches their recommendations with cautionary terms.

2) The correlations used to "prove" MGW and its crisis status (such as proxy data, glacier reference, increasing temps), are not causes, and cannot be considered proof. Correlations are not causation. Just because the bird sings every morning and the sun comes up does not mean the bird causes sunrise.

3) Since no climate scientist can say they know all of the atmospheric interactions, they make assumptions about a number of atmospheric processes, many of which are not verifiable in a lab. These assumptions drive the IPCCs computer climate models, which do not agree with one another about the climate's sensitivity.

4) Climate scientists agree that the sensitivity of the climate is not clearly understood. "There is a true climate sensitivity. We just don't know its true value." Reto Knutti

http://www.nature.com/climate/2009/0905/full/clima...

5) Observations of NASA's Aqua satellite by Dr. Roy Spencer was peer reviewed and published in the Journal of Climate. His work indicates that the IPCC models' sensitivity may be incorrect. He has actively sought comments or disagreement, none of which has been presented to date. He has also requested that his numbers be inserted in the IPCC models to see what the sensitivity forecasts would be using his data.

You well know that at least 95% of what's posted on this site is complete rubbish... from both sides of the debate. You chose examples out of the 95% of rubbish.

Your question is .... "Are there any scientific arguments against the man-made global warming theory?"

Please state your AGW hypothesis. I for one will happily oblige with a response.

EDIT Pegminer. "The lack of new statewide annual extremes could be connected with dimming due to aerosols"

This doesn't explain cooling in the Southern Hemisphere.

There are scientific arguments, but none which have passed the rigorous test of peer review (someone else willing to put heir reputation on the line to agree that the scientist is making a valid point).

I haven't seen a single peer-reviewed paper published in a leading scientific journal which casts any direct doubt on global warming or on mankind's role.

The entire appearance of a "debate" does indeed appear to ba a manufactured public relations mirage created and funded by the fossil fuel industry (American Petroleum Institute, ExxonMobil, coal lobby, etc.).

The "skeptical" fiction is sophisicated material developed by former scientists, so it's no surprise that some people here accept is as plausible to avoid any sense of personal responsibility. Of course others here are employed in the fossil fuel industry (geologists, etc), so they're just waving the denial flag in an attempt to protect their employers, their industry, and their jobs.

No, there is no competing or alternate theory.

If there was the person responsible get instant worldwide fame.

The yahoos that post here think they know something; but when you're ignorant it's easy to think you know "special" things.

I've suggested that if these people think they're so smart, why don't they go do their Ph.D.'s, with the thesis being this alternate theory, get published and get worldwide fame; just like our current world famous climatologists who have invested a lifetime of work on the question.

Nobody seems to be lining up for this job.

What it says to me is that schools and the public media-sphere have failed miserably at teaching people the content of science, the meaning of science, and the role of science as one of our most profound institutions. The world is full of crap information and it is drowning out the real information. For shame on us all.

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If you believe that real scientific organizations are biased and corrupt, and all this is some sort of manufactured problem whether overt or not, and that a better source of information is pseudo-scientific doubters and conspiracy peddlers, I’m sorry, no amount of facts or logic or information or persuasion can help you; you have a cognitive problem.

If history were true then people who research and deny the jewish holocaust would not be imprisoned (eg Earnest Zundel). The truth does not fear investigation. These laws add weight to the holocaust denial movement.

Well the way i see it global warming is a big man made joke completely fabricated. First of all the idea that men and his machines can make that much pullotion that it would accually change the atmosphere is just crazy. All man made machines cars, trucks, factories, etc.. make up less than 1% of all carbon emmissions in the world. Thank You for not believing the man made epidemic!!