Thomas,
I think you are being more than a little unfair here. I am not trying to argue anything from the historical mean temperature curve--low statistical power and iffy signal to noise, superimposed on a fluctuating background from natural fluctuations. IF that were the only argument, then there would be no argument. (In fact, reducing the science of global warming to the fitting of such data is IMO a denier tactic---sorry TM)
All of 'us' are not arguing that our folks are smarter....I link stuff cuz I think you might want to read something or drill through to the primary material, I am assuming you can digest, understand and judge the primary material.
The actual argument is one that contains many things that, when you want to, you 'take off the table', so that they can't be used in the argument.
1.
For example, models. Model building is a key component of the scientific method. Simple systems need only simple models (F=ma, Beers Law), and those get taught in schools and make some people excited because a few simple formulae capture some process nicely. However, the world also has more complex systems (the earths climate, weather, the human body responding to a pharmaceutical) that humans have a vested interest in understanding (i.e. millions of lives hang in the balance). So researchers in science and engineering don't sit around just marveling at the simplicity of E=mc2 or the second law of thermodynamics, they are trying to cobble together that basic understanding to build GPS networks, better drugs, or an understanding of how the earth works and will behave in the future. This may be distasteful to someone turned on by the coolness of the formulae when they were in school, but models are where the rubber meets the road. And in modern science and engineering these models are all mucho complicated. And computerized. And they work. Better and with more detail every year.
When you put all models aside from the discussion, and say 'garbage in garbage out' you are making a deeply anti-scientific statement (that reads a bit naive to me personally). Frankly I can't see how you describe yourself as a scientist and not believe that model building is possible.
2.
AS for the whole 'the earth is big and we are ants', I asked you to discuss the numbers. The question here is not different than balancing your checkbook. The carbon cycle has large natural flows that are (presumably) nearly in balance on the century scale, and human CO2 is a modest perturbation to that cycle, but one whose effect is additive over decades. It seems you DO agree that the higher CO2 in the air (direct measurement record) is anthropogenic. So we are ants that can increase the concentration of a significant and enduring (~few century lifetime) greenhouse gas in the atmosphere by more than 50%. Since the simple radiative balance would suggest the whole earth would be frozen without greenhouse gases, we should prob be concerned enough about this to pay some interested folks to build us a model... So this is the other thing you set aside when it suits you...someone has tried to add up the cumulative release of CO2 by humans over the last century, to tote up one column of the checkbook, and you are going to wave them away with a 'the earth is huge and we are ants' argument, after saying you did agree with the numbers!
3.
And the cherry on top is you invoking models when it suits you--cherry picking. You mention the Milankovich climate cycles. Now there is a plenty complicated model, many of whose parameters are just guesses based not on physics but on (climate) data fitting. For example, the correlation between CH4 and temp, which causes which? Has to be built in to get the model to fit. IOW, those models are not as rigorous as those to model current climate, because we can go out and measure the parameters and fluxes of the current model directly (with geologists and satellites). BUT, you cite those models as evidence that global warming is not human made. In fact, much of the early evidence (e.g. from Hansen) for AGW came from the striking departure of the earths climate in the modern period (last couple thousand years) from the record prevailing for the previous 200,000 years. That is, folks had built a kinda funky model that fits all the weird twists and turns in the earths climate through all the many ice ages, for the last 200,000 years, and it worked AWESOME at describing all the data except for the last 2000 years (1% of the record). And the only thing that happened in that period was Homo Sap started to burn down forests and till and plant stuff on continental scales and burn fossil fuels. And Mr Hansen is now hounded day and night as a hoaxer.
So, 1-2-3 you are clearly making an argument, but is it certainly not a scientific one.
