From prior post, social cost of CO2 = $39/metric ton (US Govt estimate) to $209/metric ton.
Oil and gas numbers taken from EPA calculations
CO2 from combusting one barrel of oil = 0.43 metric tons CO2/barrel
Additional amount oil should cost = 0.43($39 to $209) = $17 to $90/barrel more
CO2 from combusting one therm of natural gas = 0.005302 metric tons CO2/therm
Additional amount natural gas should cost = 0.005302($39 to $209) = $0.21 to $1.11/therm
1 therm = 100,000 BTU = 99.98 cubic feet of natural gas = $21 to $111/cubic-feet more
Coal numbers taken from EIA. Coal depends on carbon content. At 78% carbon content 1 short ton (2,000 pounds) generates 5,720 pounds. 5,720 pounds = 2.59 metric tons.
Additional amount coal should cost = $2.59($39 to $209) = $101 to $541/short-ton more.