Maryland - GHG emissions

State Insight: Maryland

Maryland (MD) reports 17.5M metric tons of CO2-equivalent in annual greenhouse gas emissions from 77 EPA-reporting facilities operated by 42 companies. Each reporting facility emits at least 25,000 metric tons of CO2e per year, the threshold that triggers mandatory disclosure under EPA's Greenhouse Gas Reporting Program (40 CFR Part 98). On a per-facility basis, Maryland averages approximately 227K metric tons of CO2e annually, reflecting the scale and mix of power generation, refining, chemicals, and heavy manufacturing within the state's industrial base.

The 42 reporting companies in Maryland span the full GHGRP sector taxonomy, but state totals are typically dominated by a small number of high-emitting operators. Top emitters visible in this dataset include HEIDELBERG MATERIALS US CEMENT, ARCLIGHT ENERGY PARTNERS FUND VII, OLD DOMINION ELECTRIC COOPERATIVE, which together reflect a disproportionate share of the MD total. This concentration pattern is consistent with national GHGRP data: roughly 100 corporate parents account for over half of all U.S. reported industrial emissions, so state-level decarbonization strategies often benefit from targeting specific facilities rather than applying uniform regulations across all reporters.

For analysts and policymakers, Maryland's profile should be interpreted against both production-weighted metrics (emissions per unit of industrial output) and population-weighted metrics (per-capita emissions). The figures above capture only Scope 1 direct emissions at reporting facilities, Scope 2 purchased electricity and Scope 3 supply-chain emissions fall outside the GHGRP's facility-level disclosure scope. State-level climate plans, including those responding to California SB 253 and forthcoming SEC climate rules, increasingly require companies headquartered or operating in Maryland to expand their disclosures beyond this baseline, making the GHGRP an important foundation but not the full picture.