Climate change is back in the news again.
First, the United Nations much-maligned Intergovernmental Panel on Climate Change reported that while “warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level,” the trend line may not be as gloomy as was predicted just a few years ago in the IPPC’s earlier report.
“The rate of warming over the past 15 years (1998-2012) of 0.05 degrees C per decade is smaller than the trend since 1951,” the IPCC group reported.
That doesn’t take any country off the hook as far as working to address not just greenhouse gas (GHG) emissions, but the impact that land use, energy consumption and agriculture al patterns have on the continuing warming trend observed since the mid-20th century. But at least it’s a ray of positive news.
Of equal, if not greater, importance are new data showing that carbon dioxide emissions from burning fossil fuels in the United States peaked at more than 1.6 billion tons of carbon in 2007. According to a new report from the Earth Policy Institute—hardly a conservative-leaning organization—they have fallen 11 percent, dropping to slightly more than 1.4 billion tons in 2013, based on estimates from the U.S. Energy Information Administration.
Of course, as expected, GHG emissions dropped rapidly during the recession that began in earnest during 2008, then bounced back up somewhat as economic conditions improved. However, the institute report noted that shifting market conditions, pollution regulations and perhaps most encouragingly, changing behaviors also contributed to the decline.
Three factors weighed most heavily in the reductions of CO2 emissions:
- Oil. As the largest source of U.S. carbon gases, petro-emissions climbed steadily from 1979 until a peak of 715 million tons in 2005. Since then, those emissions have fallen by 14 percent, or 101 million tons of carbon—“the equivalent of taking 77 million cars off the road,” the EPI report stated.
- Transportation. Not only are people driving less—more people live in urban areas, opt for public transit, work remotely or are retired—but average vehicle fuel efficiency has improved measurably in the last decade, which has reduced total fossil fuel consumption on a gallon-per-mile basis.
- Coal. It’s no secret that coal is the dirtiest fossil fuel and contributes dramatically to GHG emissions. For generations, coal dominated U.S. power production, but according to the report, its use by utilities has declined recently. Indeed, utilities are replacing or retrofitting coal-fired systems with natural gas generation, which emits about half as much CO2 per unit of energy as coal.