Friday, 24 August 2012 14:39

U.S. Carbon Emissions Lowest in 20 Years

Written by  Jessie
Detail of Tower for drilling horizontally into the Marcellus Shale Formation for natural gas, just north of Pennsylvania Route 118 in eastern Moreland Township, Lycoming County, Pennsylvania, USA Detail of Tower for drilling horizontally into the Marcellus Shale Formation for natural gas, just north of Pennsylvania Route 118 in eastern Moreland Township, Lycoming County, Pennsylvania, USA Ruhrfisch/CC BY-SA 3.0

Just when we were about to succumb to the gloomy picture that is global climate change, a ray of hope breaks through the clouds.  A technical report released this month by the U.S. Energy Information Agency calculated that energy related U.S. carbon dioxide emissions, which account for about 98 percent of total CO2 emissions, for the first four months of 2012 decreased to around 1992 levels.  

The dramatic decrease is attributed to a switch from dirtier burning coal to cleaner natural gas.  Almost everyone in the energy and environmental industries believes the shift could have major long-term implications for U.S. energy policy.

Scientists didn’t predict the amount of carbon dioxide being released into the atmosphere in the U.S. falling to its lowest level in 20 years in part because the decrease is not attributed to legislation limiting greenhouse gases such as carbon dioxide.  The switch to natural gas was driven by the market. 

The state of the economy, increasing efforts for energy efficiency and a growing utilization of renewable energy are certainly aspects that contribute to lowering U.S. carbon emissions.  However, at the moment, the lion’s share is due to the current low price of natural gas.  There has been an upsurge in shale gas drilling in the northeast, Texas, Arkansas and Louisiana, which has made natural gas more affordable than coal per unit of energy generated.  Gas production is on the increase because of the modernization of the process of hydraulic fracturing, also called fracking, where highly pressurized water, sand and chemicals are inserted to fracture shale rock which releases natural gas.

While natural gas is a cleaner-burning energy source than coal, it is not emission-free.  There is still some carbon dioxide emitted and drilling can have environmental impacts such as contamination of ground water, air quality risks, migration of gases and hydraulic fracturing chemicals to the surface, and surface contamination from spills and flowback.

There are also concerns that the rise in use of natural gas could stall renewable energy efforts.  The ultimate goal should still be a mix of increasing energy efficiency and clean energy with the balance kept to a minimum of natural gas.

So the upshot is that the U.S. energy picture is far from perfect, but the news concerning a drastic decline in U.S. carbon dioxide levels is welcome and positive because it reminds us that there is still time to turn around the fate of the planet’s climate.

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