"Back 10 or 15 years ago, everyone agreed that CO2 was up and the AGW skeptics did not agree temperature was up. The claim by the climatologists was- increased CO2 would increase temperature- and they presented a causal model based on physics for why this would happen- IR opacity and reflectivity."

As I recall 10 or 15 year ago, people were talking about the accelerated warming and pointing to the temperature graph saying this was the proof of the beginning even more accelerated warming. Now, we know by the passage of time that it was crap.
The basis of all the discussion was the signing Koyto treaty, and most countries signed it because of the merely temperature graph, it is doubtful that these countries would have signed without the 1998 jump in temperature. It's a good guess that no one who agreed to Koyto would have imagined that temperatures in next decade would never get as high, rather they imagined it was just the beginning of ever increasing temperatures.

And what some people were arguing about a decade ago, or at the moment, really lacks any significant if you won't even bother cite the specific argument.
But in the broader and important context the US Senate acted properly by overwhelming rejecting Kyoto. It's one of the better decision they have ever made- and considering overwhelming vote, almost surprising, whereas a lot of countries made the wrong decision.

I personally 10 or 15 years ago, I was less skeptical than today. Now had the trend of around 1998 continued then I would probably been less interested on the particulars of science and more convinced that whatever details of the argument some action was worth the effort. But I knew enough then that just because a graph was going up, it didn't mean it would continue. I know now that temperature could go up, but even if they do, and even if they were to continue upwards at the rate of 1998 it doesn't "prove" much- the hole that put into the "theory" by last decade of non-accelerating temperature increase, has stopped for most part the herd mentality from running over a cliff.
So "global warming" is over but it's only beginning to sink in.
But I will predict that after the panic has died and forgotten, we will reduce CO2 levels, we will get a better understanding climate, ect, and it's NOT due to people panicking- in fact the scare tactic have hindered progress. And getting back to science rather politics has been and always will be the proper course.

"15 years later, wow- we are all in agreement that we are warming. But now the new Quibble form the AGW denialist position (held almost uniformly by people who don't work in the field or research and publish in the topic) is 'Oh, Sure- theres warming, but its not caused by the CO2'.

Do you see the problem yet? "

You see things in cartoons?

"Well, lets continue.

We have the observation that CO2 concentrations and global temperatures rise in tandem, dating back into the distant past. On one hand we have a causal mechanism by which CO2 raises temperature. On the other hand we have what? Pixie dust?"

If tandem mean at a distance of couple hundred years.

We know glaciers in general stopped growing during the later part of Little Ice period [glacier activity defines that period], and majority started retreating some 150 years ago. We know generally that warming takes some time to turn around a glacier. So generally one can guess that we have had 150-200 years of conditions bringing about glacial retreat [roughly called warming]. And before the Little Ice age, there were warming periods, and warming affects ocean temperatures and if the deep ocean temperature take hundreds of years to warm [or cool] that previous warming periods are still having an affect on our oceans.

I'm not claiming it is, but as a guess the recent ocean cooling, could have something to do with the Little Ice age period, maybe something like a burp, or maybe it will last for some time. It is only a guess and probably wrong, but what reasons could explain it [the correct answer is many].
Another answer which I think might be more likely is that recent polar ice melting has cause more [not less] cold water to enter the ocean conveyors. But either are rather uninformed quesses. And I'm quite willing to listen to other possible explanations.

"Do you have any science showing how increased temperature leads to increased CO2? You do realize that the Denialist camp claimed not 5 years ago that increased temperature will lead to increased CO2 uptake by encouraging global vegetation. Do you have any science attributing the nascent warming trend to anything else?"

I should note, that you are assuming a "Denialist camp" which suggest that there is some "consensus" which holds a particular view. The only agreement one can assign to the Denialist camp, is they are in denial or what normally called skeptical- or simply what normally would be known as scientist rather than politicians or teaching institutions. You trying to frame this as though there was a school, and it's mostly involves people who have graduated and are working.

As for your specific claim, of course the increasing CO2 levels, have caused more plant growth. If nothing else you can look it in the tree rings being fatter. This isn't a matter of serious debate. And as seen on TV, there are "industries" that mine old wood, because of one reason is this wood has tighter tree rings. Trees which ten thousand year old [or older] sell at $1000 per board foot- Al Gore and all the other greenies love this stuff. Why not? It gives them a sense of history without needing to read any books.