The United States emitted less carbon dioxide through energy consumption in 2012, and while this is not the whole picture of U.S. greenhouse gas emissions, it is a welcome sign.
On Monday, the Energy Information Administration released a report showing that the carbon dioxide pollution we emit as we use energy dropped 3.8 percent in 2012. These emissions dropped from a high of 6,023 million metric tons in 2007 through a gradual drop to 5,280 million metric tons in 2012. 2011′s levels were at 5,498 million metric tons, meaning last year the country pumped out 218 million fewer metric tons of CO2 into the atmosphere.
Though U.S. CO2 emissions in 2012 amounted to 368,000 pounds of pollution per second, this is the lowest level since 1994:
The drop in 2009 was largely due to the contraction in the U.S. economy during the Great Recession, yet the falling carbon dioxide emissions in 2012 occurred while GDP rose 2.8 percent. Energy consumption fell by 2.8 percent.
The main reason for this is that American energy intensity dropped — energy use per dollar of GDP fell 6.5 percent. The economy was able to do more with less energy, which has been a long-term trend ever since an inefficient high in 1970. Wasting energy is bad for everyone except the people who sell fuel and electricity (and sometimes even they prefer to sell less).
The United States also has continued a decade-long trend of generating more electricity from natural gas and less from coal. Coal emits more CO2 when it is burned than natural gas does. Renewable energy became a larger element of the energy portfolio in 2012. So not only did many consumers use less energy to go about their lives, the energy they used also required less carbon dioxide to be burned.
Finally, 2012 had a warmer winter and therefore required less energy to heat homes and businesses. Americans also drove, on average, the same number of miles per day in 2012 as they did in 2011, but with more efficient vehicles continuing to enter the market, transportation sector emissions dropped 22 percent.
Pennsylvania State University climate scientist Michael Mann told the AP that the drop “is reason for cautious optimism that we’re already starting to move in the right direction, but this alone will not lead us toward the dramatic carbon reductions necessary to avoid dangerous climate change.”
The report is careful to just refer to “energy-related carbon dioxide emissions” dropping — why not just say greenhouse gas emissions dropped, or carbon emissions fell in 2012?
The answer is we will not know if either of those things are true until April 2014. EIA used to release a full inventory of all greenhouse gas emissions but now leaves that job to the EPA.
So CO2 emitted from the production of energy — flaring natural gas wells, transporting oil, coal, and gas to market, for example — is not included in the EIA numbers. Neither is carbon dioxide emitted through biomass energy production, though the argument can be made that biomass such as ethanol and wood are not “emitted” in the same way as fossil fuels.
And this does not even begin to cover other greenhouse gases. Methane, nitrous oxide, and other super-potent greenhouse gases are not in this report. The full numbers of the rest of U.S. greenhouse gas emissions will be released in April 2014 through the EPA’s Inventory of Greenhouse Gas Emissions and Sinks.
The total greenhouse gas emissions mostly track with the EIA’s carbon dioxide energy-related numbers, and carbon dioxide makes up 84 percent of total American greenhouse gas emissions. But it is important to note that these numbers are not identical, and to avert the worst impacts of climate change, the U.S. will have to lower all greenhouse gas emissions, not just carbon pollution.