Energy-related carbon emissions fell 3.8 percent last year, according to new data released by the federal Energy Information Administration.
The Washington Post explains why the downward trend in the U.S. may not last:
For one, carbon dioxide emissions for energy have already risen 2.6 percent (year over year) in the first half of 2013, according to preliminary data. And the Energy Information Administration expects emissions to keep rising over the next few years:
Why the rebound in emissions?
Over the past few years, natural gas prices have been abnormally low, dropping below $2 per million BTU, as a flurry of fracking operations and lack of storage facilities produced a glut of shale gas on the market. Coal got crushed. Now the market’s finally settling down, gas prices have rebounded somewhat, and coal is clawing back some of its market share.
Although U.S. emissions have been falling, globally they’ve been going up.
Last month for the first time, scientists from the Intergovernmental Panel on Climate Change recommended a carbon budget for the planet.
No more than one trillion metric tons of carbon could be burned and the resulting gases released into the atmosphere, the panel found, if planetary warming is to be kept below 3.6 degrees Fahrenheit (2 degrees Celsius) above the level of preindustrial times. That temperature is a target above which scientists believe the most dangerous effects of climate change would begin to occur.
According to a 2009 state report, Pennsylvania is responsible for one percent of the world’s greenhouse gas emissions.