Those calculated externalities seem to be based on a fixed carbon tax. They don't take into account the human cost of living near a coal-fired plant (including productivity loss!), the financial damage of oil and oil-byproduct spills, or water table pollution from fracking.
Each of these externalities, in turn, has consequences of their own -- fewer tourists, increased cost-of-living from bottled watter, higher medical bills from persistent lung and throat disorders. If harm to individuals isn't compelling, consider the danger of a polluted water table to predominantly agricultural areas.
The NCPA doesn't consider these realities in their flat estimation and, based on their sources of funding, are not likely to in the near future [1].
[1]: https://www.theguardian.com/environment/2009/jul/01/exxon-mo...