WASHINGTON — President Obama will use his executive authority to propose a global warming regulation that would cut carbon pollution from the nation’s coal-fired power plants by up to 20 percent and pave the way for the creation of state cap-and-trade programs without having to go through a reluctant Congress, according to people familiar with the rule.That sounds big, and getting rid of 20% of coal in the U.S. would be a significant first step, but the CO2 problem is so large the overall impact isn't that impressive.
In 2013 the U.S. emitted 5,393 megatonnes of CO2 from burning fossil fuels, according to the EIA. Of that, 1,722 Mt was from burning coal.
So a 20% maximum reduction in the latter is only 344 Mt, or 6.4% of the total, maximum.
And it's about 1% of global emissions.
6% is much better than nothing. Do it 16 times and you're almost down to zero. But it just shows how enormously difficult it is to make climatologically meaningful cuts in carbon emissions. It's most meaningful impact may be the message, to the country and the world (especially the Chinese).