The social cost of carbon is a unit of measure. It measures the economic damage caused by a ton of carbon dioxide emissions.
"A recent U.S. government study concluded, based on the results of three widely used economic impact models, that an additional ton of carbon dioxide emitted in 2015 would cause $37 worth of economic damages. These damages are expected to take various forms, including decreased agricultural yields, harm to human health and lower worker productivity, all related to climate change.
But according to a new study, published... in the journal Nature Climate Change, the actual cost could be much higher. 'We estimate that the social cost of carbon is not $37 per ton, as previously estimated, but $220 per ton,' said study coauthor Frances Moore, a PhD candidate in the Emmett Interdisciplinary Program in Environment and Resources in Stanford's School of Earth Sciences."
Source: Stanford University News, Jan 12, 2015
SCC is a critically important concept. We're in this problem because many of us are internalizing the benefits of carbon while externalizing the costs of carbon.
It's one thing to become carbon neutral (the sooner the better obviously), but it's even more powerful to stop externalizing costs to the most vulnerable.
That's what the SCC helps us to do. It forces us to acknowledge that if we wait to become carbon neutral we are, in effect, choosing to continue damaging the most vulnerable.
If the average American household emits 40 mtCO2e annually, that means the average American household shifts $8,800 in social costs onto others -- often the most vulnerable.