Fig. 4.

CO₂ price sensitivities. A shows the implications of technological change and TP assumptions. Setting ${\phi }_0=0\%\hspace{0.17em}{\phi }_1=0$ increases early-year and final-period prices, flattening the price path. Multiple TPs act akin to fattening the tail of the damage function, steepening the price path. They also interact with the no-technological-change assumption, increasing final-period prices. B shows that 2015 CO₂ prices depend crucially on “catastrophic” climate risk assumptions, set to $peakT=6^{○}$C and $disaster\hspace{0.17em}tail=18$ in the base case (Climate Damages). C, by contrast, shows the minimal implications of extending the final period from 2300 to 2400 for $t=6$ and 7, respectively, in the base case to 2400 and 2700.