and
"The moralising stridency of so many arguments for cap-and-trade, carbon taxes, and global emissions treaties was founded on the idea that there is a consensus about how much warming there would be if carbon emissions continue on trend. The rather heated debates we have had about the likely economic and social damage of carbon emissions have been based on that idea that there is something like a scientific consensus about the range of warming we can expect. If that consensus is now falling apart, as it seems it may be, that is, for good or ill, a very big deal."