You haven't offered one. But I am getting ready to leave and probably won't get much chance to really look at it for today.
It's more about the rate of change than the maximum temperature that might be achieved. It appears from the climate records that the main control of atmospheric CO2 concentrations on 1,000-10,000 year scales is the overall temperature of the ocean. Milankovitch forcing (orbital and rotational changes) influences the total insolation that the Earth receives, i.e. the energy input from the Sun. The climate "tends" toward an equilibrium, which is sensitive to the atmospheric CO2 concentration -- higher CO2 concentrations help to maintain warmer conditions, lower concentrations help to maintain colder conditions.
Milankovitch forcing pushes the Earth's climate into transitions, notably the glacial/interglacial transitions (the big peaks and valleys in the graph), but many of the minor changes are also related to the Milankovitch cycles.
The transitions alter the Earth's radiative balance, which in turn forces the climate system to adjust the equilibrium temperature. As the oceans cool or warm in the system, atmospheric CO2 will decrease (cooling oceans absorbs more CO2) or increase (warming oceans release CO2). It takes several hundred years for the new equilibrium to "hold" after a major transition. When equilibrium exists, temperatures generally only change 0.2 C per century or less.
What is happening now is that atmospheric CO2 is increasing without any external forcing, a very unusual situation in a relatively stable climate regime (which was the point of the first graph). The climate system will respond to this, and the questions that need to be answered are by how much and how fast. Ecosystems can adjust to change, but there are limits to how quickly then can respond, and the alternate to responding is collapsing. Rapid changes are always the most difficult to mitigate (which seems obvious, but that's the core of the issue).
And I'd like to add after re-reading: another control atmospheric CO2 on 1,000-10,000 year time scales is the amount of carbon sequestered in wetlands, like peat bogs. In a warming climate, peat bogs and other wetland systems will also release CO2 as biomass respiration accelerates.
Astronomical Theory of Climate Change
The Paleoclimate Record and Climate Models (long but comprehensive)
And if you really, really want to get into this heavily: AS235/OBEE238: Ocean Biogeochemical Dynamics and Climate has a smorgasbord of links, including a link to the online book "Ocean Biogeochemical Dynamics"
You might find subchapter 10.4 of interest.