During 2010-18 in Arlington, the use of natural gas rose by 30 percent to 91 million therms while use of electricity fell by 9 percent to 3.1 billion kilo watt hours, according to data from the Arlington County Government. In terms of carbon emissions, total carbon emissions declined by about 4 percent during 2010-2018, but most of this occurred because of lower commercial and government use related to fewer office workers in Arlington.

Residential use of electricity and natural gas both rose in this period. Use of electricity in homes rose by 3 percent to 1.7 billion kilowatt hours, and use of natural gas by rose by 54 percent to 61 million therms. Combined carbon emissions in residences rose by 14 percent to about 1.1 million metric tons of carbon. Raw data were supplied by the county government and converted to carbon equivalents using EPA data.

The increased residential use was propelled upwards by a 9-percent rise in population of Arlington rising to about 226,000 in January 2019 from 208,000 in 2010. However the rise in energy use exceeded the rise in population indicating that residents are intensifying their use of energy in their homes.
For the commercial and government sectors which experienced a drop in gas and electricity use, the large increase in empty office space and the reduction in the number of federal employees located in Arlington triggered this decline.

With the expected entry of thousands of Amazon employees in Arlington over the next 5 years or so, it is likely that the commercial sector will return to its prior energy use as office space is filled and more office buildings are constructed.

The Arlington Community Energy Plan adopted in 2013 has thus yet to indicate a shift in the energy patterns in commerce, government and residential uses, and the slight 4-percent drop in carbon emissions is entirely related to increased office vacancies. A return to high office use and the entry of Amazon HQ2 is likely to lead to a rise in overall county emissions. This will make impossible Arlington County’s energy plan goal to attain a 50-percent drop in emissions in the next 20 years.