According to this report by the World Bank, 40 nations and 20 smaller jurisdictions are already pricing carbon (aka: taxing carbon), representing a quarter of the world’s green house gases. The amount of carbon pricing has grown 300% in the past decade. The carbon pricing instruments in these jurisdictions cover about half of their total GHG emissions (approximately 7 gigatons of CO2), which is circa 12% of annual global GHG emissions. The combined valuation of all carbon pricing worldwide in 2015 was estimated at $50 billion per year.
