As a result, emissions of carbon - dioxide in the United States in 2012 fell to levels not seen for two decades, due
mainly to
fuel -
switching from coal to natural gas, according to the U.S. Energy Information Agency.
In particular, depending
mainly on (i) exactly how much abatement might be required over 2019 - 23, (ii) the amount and availability of combined - cycle gas - turbine (CCGT) generation capacity with the required efficiency levels, and (iii) the evolution of commodity prices between now and 2021, the carbon price required to plug the supply gap could be lower or higher than the levels we have imputed from our modelling of the supply - demand dynamics in the EU - ETS over 2019 - 23, and the
fuel -
switching price levels implied by current forward curves.