Methodology & Data Sources

Data Source

All emissions data on PlainCarbon comes from the EPA Greenhouse Gas Reporting Program (GHGRP), a mandatory reporting program established under Section 114(a) of the Clean Air Act. Since 2010, U.S. facilities emitting 25,000 metric tons of CO2-equivalent or more per year are required to report their emissions to the EPA annually.

Source URL: epa.gov/ghgreporting (EPA GHGRP / FLIGHT tool)

Data Coverage

  • Time period: 2011–2023 (13 years)
  • Facilities: ~8,737 reporting facilities
  • Emissions type: Scope 1 direct emissions (CO2, CH4, N2O, fluorinated gases)
  • Unit: Metric tons CO2-equivalent (MT CO2e)

Company-Level Aggregation

PlainCarbon aggregates facility-level emissions to the parent company level using EPA's own parent company attribution data, which maps facilities to their corporate owners as of the most recent reporting year (2023). This allows comparing total corporate emissions, not just individual facility footprints.

Important: Parent company attribution is based on 2023 ownership and may not accurately reflect historical corporate structure for earlier years. Mergers, acquisitions, and divestitures between 2011–2023 are not retroactively adjusted.

How We Process the Data

  1. Download EPA GHGRP facility-level emissions data for each year (2011–2023)
  2. Parse facility name, parent company, EPA sector, state, and total GHG emissions by gas type
  3. Join with EPA parent company attribution table to build company-level profiles
  4. Aggregate facility emissions to company totals for each year
  5. Compute 13-year trends, industry sector rankings, and state rankings
  6. Load into our search-optimized database

Scope 1 vs. Scope 2 vs. Scope 3

GHGRP captures Scope 1 (direct) emissions only - emissions produced directly by a company's own operations. It does not include:

  • Scope 2 - Indirect emissions from purchased electricity, heat, or steam
  • Scope 3 - Value chain emissions (suppliers, products in use, end-of-life)

For many companies, Scope 2 and 3 emissions can be larger than Scope 1. PlainCarbon's data is useful for comparing direct industrial emissions but should not be used to assess a company's total climate impact.

Limitations

  • Only facilities emitting ≥25,000 MT CO2e/year are required to report, smaller facilities are excluded
  • Emissions data represents what companies self-report to EPA, not independently verified values
  • Parent company attribution reflects 2023 ownership, not historical structure
  • Industry classifications follow EPA sector designations and may differ from other systems (SIC, NAICS)

How the Source Agency Collects Data

Under the EPA Greenhouse Gas Reporting Program, facilities that emit 25,000 metric tons or more of CO2-equivalent per year must calculate and report their direct greenhouse gas emissions annually using EPA-specified calculation methodologies. These methods include continuous emissions monitoring systems (CEMS), fuel-based calculations using emission factors, and mass balance approaches, depending on the industry sector. Facilities submit their reports through the EPA's electronic Greenhouse Gas Reporting Tool (e-GGRT) by March 31 of each year for the prior calendar year's emissions.

The EPA verifies submitted data through a multi-step quality assurance process that includes automated electronic checks, statistical analyses, and targeted data verification for outlier reports. Facilities must retain records supporting their emissions calculations for at least five years.

Data Accuracy Commitment

PlainCarbon presents EPA GHGRP data without modification. Emissions figures, facility attributions, and sector classifications are displayed exactly as reported to and published by the EPA. We do not estimate Scope 2 or Scope 3 emissions, and we do not compute our own environmental rankings beyond what the data directly supports. If you find any data that appears incorrect, please contact us and we will verify against the EPA source data.

Editorial Workflow

Content on PlainCarbon is compiled by our editorial team. Raw emissions data from the EPA Greenhouse Gas Reporting Program (FLIGHT/GHGRP), the EIA, and state environmental agencies is ingested programmatically by our ETL pipeline; narrative framing, facility profiles, rankings commentary, guide text, and methodology writeups are drafted by our editorial team and then reviewed line-by-line by the PlainCarbon editorial team before publication. We follow rigorous editorial standards: source data is loaded directly from official agencies, never invented or interpolated. No page on PlainCarbon is published without human review. We do not accept payment for coverage, placement, or rankings, facility lists, rankings, and industry sector breakdowns are computed directly from the source data.

Frequently Asked Questions

Where does PlainCarbon's emissions data come from?

All facility and company emissions data comes from the U.S. Environmental Protection Agency's Greenhouse Gas Reporting Program (GHGRP), accessed via the EPA FLIGHT tool. Supplementary context draws on the U.S. Energy Information Administration (EIA) and, where applicable, state environmental agencies.

How often is the data updated?

The EPA releases GHGRP data annually, typically in the fall, covering the prior calendar year. PlainCarbon refreshes its database within 30 days of each upstream EPA publication. Between releases, facility-level figures on the site reflect the most recent reporting year published by EPA.

How accurate are the emissions figures?

Emissions are self-reported by regulated facilities using EPA-specified calculation methodologies (continuous monitoring, fuel-based emission factors, or mass balance), and EPA performs automated checks, statistical analyses, and targeted verification of outlier reports. PlainCarbon presents these figures unchanged, we do not independently audit individual facility reports.

What are the limitations of this data?

Only facilities emitting ≥25,000 MT CO2e per year are required to report, so smaller sources are excluded. GHGRP covers Scope 1 direct emissions only, not Scope 2 (purchased energy) or Scope 3 (value chain). Parent company attribution is based on 2023 ownership and may not reflect historical corporate structure for earlier years. Industry sector labels follow EPA classifications, which can differ from SIC or NAICS systems.

Contact

Questions about our methodology or found a data error? Reach us at hello@plaincarbon.com or through our contact page.

Related Federal Resources

Beyond our primary data sources, the following federal government resources provide additional context for transparency, methodology verification, and related public records:

  • FOIA.gov - Freedom of Information Act portal for requesting federal records.
  • USA.gov Government Works - Comprehensive directory of U.S. federal agencies and public datasets.
  • Data.gov - Central repository of U.S. federal open data, including the source agencies referenced on this page.
  • Regulations.gov - Federal Register notices, public comments, and rulemaking activity for source agencies.
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