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PERI Greenhouse 100 Polluters State Press Release For Oklahoma

November 6, 2025

 

With Future Data in Doubt, UMass Amherst Political Economy Research Institute Names Top U.S. Climate Polluters

Rollback in EPA reporting requirements may end Greenhouse 100 Polluters Index and access to vital public information

AMHERST, Mass. — Researchers at the University of Massachusetts Amherst’s Political Economy Research Institute (PERI) today published a new Greenhouse 100 Polluters Index, reporting 2023 greenhouse gas emissions using the latest—and possibly last—data available from the U.S. Environmental Protection Agency’s Greenhouse Gas Reporting Program.

On Sept. 12, the EPA announced plans to end most of the program and suspend all remaining reporting requirements until 2034. The decision could leave the public without reliable, standardized data on corporate climate pollution for nearly a decade.

“The Greenhouse 100 Index informs consumers, shareholders, regulators, lawmakers and communities about corporate releases of climate-altering pollutants into our environment,” says Professor Michael Ash, co-director of PERI's Corporate Toxics Information Project. “The EPA’s decision to effectively end the Greenhouse Gas Reporting Program removes access to vital public information and leaves public and private decision-makers flying in the dark or relying on a patchwork of voluntary and potentially cherrypicked or greenwashed reports.”

Launched in 2018, PERI’s free, open-access online tool provides data on every company that reports to the EPA. The resource includes state-by-state rankings and detailed reports identifying all companies and facilities responsible for each state’s greenhouse gas emissions. Archives of earlier editions remain available to the public.

The following is PERI's analysis for Oklahoma.

Overall

Summary for OklahomaValue
Total 2023 CO2 equivalent emissions (millions of metric tons):70.2
Percentage of national total:2.7
Rank among US states (1=top):10

Top 5 Polluter Companies in Oklahoma

CompanyCO2 equivalent emissions (mmt)% of state totalNum. facilities
OGE Energy9.014.710
American Electric Power5.18.36
CF Industries4.57.42
Devon Energy4.57.310
Williams Companies4.06.514

Top 5 Sectors in Oklahoma

Sector NameCO2 equivalent emissions (mmt)Num. facilities
Power Plants26.428
Onshore Petroleum & Natural Gas Production12.759
Petroleum & Natural Gas Gathering & Boosting9.146
Ammonia Manufacturing5.74
Petroleum Refineries4.45

Top 10 facilities in Oklahoma

Facility NameCO2 (metric tons)Company
VERDIGRIS PLT3,354,663CF Industries
Northeastern3,140,720American Electric Power
Chouteau Power Plant2,606,111Associated Electric Cooperative Inc
KOCH FERITLIZER ENID LLC ENID NITROGEN PLT2,379,962Koch Industries
Oneta Energy Center2,279,970Argo Infrastructure Partners
Tenaska Kiamichi Generating Station2,201,473Kiowa Power Partners LLC
Williams G&B Facility Appalachian Basin (Eastern Overthrust Area) 160A2,138,544Williams Companies
Redbud Power Plant2,087,378OGE Energy
Grand River Dam Authority1,969,971State of Oklahoma
Phillips 66 Ponca City Refinery1,899,802Phillips 66

“In making this information available, we are building on the historic achievements of the right-to-know movement,” Ash adds. “Our goal is to engender public participation in environmental decision-making, and to help residents translate the right to know into the right to clean air, clean water and a livable planet.”

The EPA’s rollback of reporting and disclosure requirements also threatens other PERI indexes that track companies’ release of pollution into the air and water, and near schools.

Contacts:
Michael Ash, mash@umass.edu

Aaron Kupec, akupec@umass.edu