A new paper has appeared in Nature Climate Change which puts a social cost of global warming at $200 per ton of carbon dioxide. The authors are Frances Moore and Delavane Diaz of Stanford.
The SCC is of course is a figure that greens can manipulate pretty much to their hearts' content - witness Frank Ackerman's hilarious $1000 figure of a few years back. The entertainment comes in working out what particular dodges have been pulled to hike the figure upwards and the new paper explains that it is picking up on an earlier study by Dell et al, which sought to make revised estimates of the damage that climate change would cause by examining the effect of short-term fluctuations in the weather on economic output.
Everyone involved is admirably open about the fact that this is what they are doing, and the fact that weather damage is something completely different to climate effects. You read that they have taken steps to estimate the difference, but I'm not sure that they are going to convince anyone that what they are doing is anything other than sticking a finger in the air. But then you also read that they are working with warming in 2100 of over 4.5°C; in other words they are using the IPCC's absurdly overegged RCP8.5 scenario. Needless to say, this is described as "business as usual". They are also using the IPCC's GCM-based estimates of climate sensitivity.
At this point you realise that you are being had, and you read no further.