When coal's generation market share rises, carbon emissions go up. When natural gas's generation market share goes down, carbon emissions go up. And US carbon emissions are going back up.
After declining 3.9% in 2012, US carbon emissions are going up 2.4% in 2013 and 0.6% in 2014, according to the most recent report of the Energy Information Administration.
Why the rising carbon emissions? At page 9 of the Report, the EIA states:
"The increase in emissions over the forecast period primarily reflects the projected increase in coal use for electricity generation, especially in 2013 as it rebounds from the 2012 decline." That's to the point!
Carbon emissions declined 3.9% in 2012, in large part because natural gas displaced big amounts of coal generation. Indeed, coal's electricity generation market share fell to 37% in 2012 and is now back to 40%, as higher natural gas prices has meant that coal this year is displacing gas in power markets.
The 2.4% increase this year in carbon emissions means about 125 million more tons of carbon dioxide will be emitted than in 2012. Then in 2014 carbon emissions will be about 155 million tons more than in 2012.
Over the two years, the additional carbon dioxide in the atmosphere will be about 280 million tons or a little less than 1% of annual global emissions. Simply put, it is a lot.
That extra 280 million tons of carbon dioxide will remain in the atmosphere for more than 100 years trapping heat. The only silver linings in this dark cloud is that US carbon emissions in 2014 may still be lower than they were in 2011, even after increases in both 2013 and 2014.
But the question becomes, did US carbon emissions bottom in 2012 and have they begun a sustained climb once again?