One interesting fact is that alarmists have to deal with the lack of warming or increase in ocean heat content over the last 12 years or so. They will argue that this is just a temporary aberration, and a much shorter time frame than they are working on. Let’s think about that.
Here is the core IPCC argument: for the period after 1950, they claim their computer models cannot explain warming patterns without including a large effect from anthropogenic CO2. Since almost all the warming in the latter half of the century really occurred between 1978 and 1998, the IPCC core argument boils down to “we are unable to attribute the global temperature increase in these 20 years to natural factors, so it must have been caused by man-made CO2.” See my video here for a deeper discussion.
In effect, the core IPCC conclusions were really based on the warming over the 20 years from 1978-1998. There was never any implication that their models couldn’t explain, say, the 1930’s or the 1970’s without manmade CO2.
So while 12 years is admittedly short compared to many natural cycles in climate, and might be considered a dangerously short period to draw conclusions from, it is fairly large compared to the 20 year period that drove the IPCC conclusions.
Here is where we stand: The IPCC models supposedly cannot explain the 20 year period from 1978-1998 without factoring in a high climate sensitivity to CO2. However, I would venture to guess that, prior to tweaking, the IPCC models cannot explain the 12 year period from 1998-2011 while still factoring in a high climate sensitivity to CO2.
Postscript: I suppose the IPCC would scream “aerosols,” but even putting aside the equivocal and sometimes offsetting effects of aerosols and black carbon, I do not think one could reasonably argue their effect was much greater in one period than the other.