The Carbon Footprint of Development

The Prince William Board of County Supervisors voted in the fall of  2020 to adopt the Metropolitan Washington Council of Governments’ Region Forward Vision’s sustainability goal that calls for a decrease in greenhouse gas emissions of 50 % below 2005 levels by 2030.

The Board of County Supervisors went further in their resolution and directed staff to incorporate into the Comprehensive Plan goals of 100% of Prince William County’s electricity to be from renewable sources by 2035, for Prince William County Government operations to achieve 100% renewable electricity by 2030, and for Prince William County Government to be 100% carbon neutral by 2050.

That is a very short time horizon. From the Citizens’ Climate Lobby, we know that “Metropolitan Washington Council of Governments developed a greenhouse gas inventory for PW County, covering the base year 2005, plus 2012, 2015, and 2018 (the most recent year available). The inventory covers 6 sectors, and 22 source types, and it uses standard methods for GHG inventories.”

“The results indicate that PWC’s emissions increased 19% between 2005 to 2018. (For comparison, Fairfax county decreased by an almost equal amount.) The top four source of greenhouse gases represent 83% of total:

• On-road vehicles (33% of 2018 total; 13% increase since 2005)
• Commercial buildings – electricity (27% of 2018 total; 113% increase since 2005)
• Residential buildings – electricity (15% of 2018 total; 18% decrease since 2005)
• Residential buildings – natural gas (8% of 2018 total; 31% increase since 2005)”

From the U.S. Energy Information Administration we know that in Virginia electricity generation had increased by about 30% over the past 10 years, yet due to a change in the fuel mix has led to the mass emissions levels remaining relatively constant. Over this period of time a major shift has occurred in the Virginia power sector where electricity generation from coal has been replaced by cleaner generation sources of natural gas and more recently renewable energy generation sources. The electricity used in commercial operations has more than doubled since 2005. An significant portion of the increased demand for electricity is due to the construction of data centers in Northern Virginia.  In the past decade Virginia has become the world's data center capital which might account for the unpresented growth in electricity demand in the state.

To hit PW County’s 50% greenhouse gas emission reduction goal by 2030, we will need to reduce emissions to 2.1 MMTCO2equivalnts. This amounts to a  58% reduction in GHG emissions from 2018 levels, and current levels are probably higher given the continued build out of data centers within the county in the last four years. Realistically, that is simply not going to happen. As the Citizens’ Climate Lobby pointed out in their review of the Comprehensive Plan, “Even if the electricity grid were to be 100% renewable by 2030 (a far more optimistic projection than is credible), it would only achieve a 42% reduction from the 2018 levels.”

How do we achieve this goal? Certainly, not by ignoring the impact on greenhouse gas emissions from the zoning changes, land use changes, preservation and other decisions by the County Staff and elected officials. The main drivers increasing emissions are primarily growth in population, commercial space, and emissions from transportation- all characteristics of the changing face of Prince William County. There were some factors that reduced emissions over the period; a less carbon-intensive electric grid, decreased commercial electricity energy intensity, and cleaner cars. However, the impact of increased commercialization and population overwhelmed the reductions.  

The Citizens’ Climate Lobby believes that in Prince William County, “forested lands stored about 740,000 tons of carbon per year, or about 15 % of the county’s gross emissions.” The Citizens’ Climate Lobby goes on to argue that “carbon storage needs to be a huge part of the equation, and land use is the means of influencing carbon storage.” A program of planting trees and reforestation of certain areas could reduce the county carbon footprint, but not if we clear agricultural and wooded land, level it and build data centers. Just take a look at what is happening along 234 in Manassas.  

What we need to do is begin by incorporating an analysis of greenhouse gas emissions impact of all projects, and plans in the county so that this important goal can be monitored in real time. We can see the carbon impact of zoning proposals, the comprehensive plan and special use permits. With data  our county staff and supervisors can steer the county to the future they imagine for us.