10 Degrees in Two Hundred Years?

I suppose a couple of cautions are in order:   I haven't seen any of the big names in climate science comment on this yet, and one of the authors is a Greens politician;  but still, this seems an interesting look at what may happen if you were to burn all fossil fuel reserves.  The abstract:

Concrete actions to curtail greenhouse gas emissions have so far been limited on a global scale¹, and therefore the ultimate magnitude of climate change in the absence of further mitigation is an important consideration for climate policy². Estimates of fossil fuel reserves and resources are highly uncertain, and the amount used under a business-as-usual scenario would depend on prevailing economic and technological conditions. In the absence of global mitigation actions, five trillion tonnes of carbon (5 EgC), corresponding to the lower end of the range of estimates of the total fossil fuel resource³, is often cited as an estimate of total cumulative emissions^{4, 5, 6}. An approximately linear relationship between global warming and cumulative CO₂ emissions is known to hold up to 2 EgC emissions on decadal to centennial timescales^{7, 8, 9, 10, 11}; however, in some simple climate models the predicted warming at higher cumulative emissions is less than that predicted by such a linear relationship⁸. Here, using simulations¹² from four comprehensive Earth system models¹³, we demonstrate that CO₂-attributable warming continues to increase approximately linearly up to 5 EgC emissions. These models simulate, in response to 5 EgC of CO₂ emissions, global mean warming of 6.4–9.5 °C, mean Arctic warming of 14.7–19.5 °C, and mean regional precipitation increases by more than a factor of four. These results indicate that the unregulated exploitation of the fossil fuel resource could ultimately result in considerably more profound climate changes than previously suggested.