Any price you put in place will establish a threshold, so that the market then has an incentive to find the emission reductions that cost less than that amount per tonne. We would expect that, already at the $20 to $30 range, we would be seeing the market working to find those.
In the case of motor fuels, demand elasticities are very low. Demand is very resilient. In that case, it's possible to calculate. I believe the number we would need as a carbon price to hit Paris targets would be about $230 or $240 a tonne.
A better question at that point would be what an appropriate price per tonne is as far as the estimated social damages go. That may not be consistent with specific targets like net zero and Paris.