Loudoun County—followed by Prince William County—has undermined the climate progress made by the rest of Northern Virginia. MWCOG’s Mid-Course Review shows that most neighboring jurisdictions reduced greenhouse-gas emissions between 2005 and 2023, while emissions rose sharply in the two counties that approved the region’s largest concentrations of hyperscale data centers. The operating facilities already built, together with the enormous additional load in the development pipeline, are not merely local land-use decisions: they are reshaping electricity demand across Virginia and the wider PJM grid. Unless that growth is constrained or matched with additional carbon-free generation, storage, transmission, and enforceable clean-energy requirements, Virginia cannot remain on the decarbonization trajectory established by the Virginia Clean Economy Act (VCEA), and PJM’s transition away from fossil generation will be delayed.
Two Counties Reversed the Regional Climate Trend
From 2005 to 2023, Arlington and Fairfax counties cut gross
emissions by 33% and 27%, respectively. Those gains were offset by Prince
William County’s 19% increase and, above all, Loudoun County’s extraordinary
130% increase. Net emissions rose even faster in Loudoun and Prince William
because development also removed forests and other carbon-sequestering land.
The result is a stark regional inequity: communities that reduced energy use
and emissions are seeing their progress eroded by data-center approvals
concentrated in two Northern Virginia jurisdictions.
Loudoun County Created the Region’s Largest Carbon Load
Loudoun County is the principal source of the regional
divergence. Its transformation into the world’s largest data-center market
drove a 130% increase in gross emissions and a 145% increase in net
emissions from 2005 to 2023, despite the region’s adopted climate targets.
Loudoun’s land-use approvals converted what had been a manageable regional
emissions-reduction challenge into a rapidly expanding electricity-demand
problem that reaches far beyond the county’s borders.
·
Local approvals produced a permanent
industrial load: The pandemic temporarily reduced transportation and office
emissions, but data centers operate continuously. Loudoun’s community-wide
emissions had already risen 54% by 2020 compared with 2005; by 2023, the
accelerating data-center buildout had pushed the gross increase to 130%. This
was not a short-lived post-COVID rebound. It was the predictable result of
approving a new class of round-the-clock industrial electricity demand.
- Sector
Concentrations: Because MWCOG applies a location-based electricity
emissions factor, the electricity consumed inside the county maps directly
to Loudoun’s inventory. Commercial grid electricity consumption within the
Built Environment sector constitutes the vast majority of Loudoun's
footprint, outstripping the combined emissions of the residential and
transportation sectors.
- Carbon
Sequestration Deficit: In 2020, Loudoun's forest canopy sequestered
430,000 metric tons of CO2 equivalent, offsetting
roughly 7% of total emissions. However, ongoing land grading and
industrial expansions have driven the county’s net emissions
increase (+145%) higher than its gross increase (+130%),
highlighting the loss of natural carbon sinks of the tree canopy.
Prince William County Copied Loudoun’s Example
Prince William County then followed Loudoun’s development
model, approving major data-center corridors and adding another rapidly growing
block of continuous industrial demand. This all took place right after the
PWBOCS voted to approve climate goals for the County. By 2023, the county’s
gross emissions were 19% above the 2005 baseline and net emissions were 22%
higher. Instead of helping counterbalance Loudoun’s extraordinary increase,
Prince William compounded it—further weakening the region’s ability to meet its
collective climate commitments.
- The
Multi-Year Trajectory: PWC's community-wide emissions grew from 4.16
million metric tons of CO2 equivalent in 2005 to 4.96 million metric
tons of CO2 equivalent in 2018—a 19% increase prior to the
pandemic. While per-capita emissions initially dropped 10% due to rapid
population growth outstripping emissions pacing (+32% population vs +19%
emissions), the post-lockdown industrial expansion stabilized the
footprint at a persistent 19% gross and 22% net increase by 2023. Since
that time data centers continued to come on line.
- Sector
Breakdown Trends: Historically, PWC’s emissions were led by energy
consumption (residential and commercial) at 54% and transportation at 38%.
Post-lockdown data shows commercial grid consumption increasing its share
of the pie, driven by the expansion of data center corridors along Route
234 and the Innovation Park tech zone.
- Canopy
Degradation: PWC’s forest canopy provides net sequestration of more
than 368,000 million tons of CO2 equivalent annually. Similar to Loudoun,
massive land-use changes for new industrial campuses and right-of-way
transmission lines have widened the gap between gross (+19%) and net
(+22%) emission baselines.
The Consequence: Virginia and PJM Cannot Decarbonize on
Schedule Under the Current Load-Growth Path
The consequences now extend well beyond county boundaries.
The VCEA requires Dominion Energy to move toward 100% carbon-free electricity
by 2045, but the data centers already operating—and the much larger pipeline under
construction or approved in Loudoun and Prince William—are causing electricity
demand to grow faster than clean generation and transmission can be added.
Under that trajectory, new renewable resources must first chase new data-center
load rather than displace existing fossil generation. The practical effect is
to postpone coal and gas retirements, increase pressure for new gas-fired
resources and imports, and make the statutory VCEA timetable increasingly
difficult if impossible to achieve.
1. Virginia’s
problem becomes PJM’s problem: Dominion is part of the multi-state PJM
system. When Northern Virginia’s continuous data-center load exceeds the pace
at which Virginia can add carbon-free supply, PJM must commit additional
generation somewhere in the regional fleet. Because marginal and reliability
resources remain heavily dependent on natural gas and coal, local approvals in
Loudoun and Prince William can prolong fossil generation and associated
transmission investments across multiple states.







