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Measuring Carbon Emissions from Above

• Global Airborne Observatory: On September 2, 2023, this specialized aircraft flew over the Colstrip coal-fired power plant in Montana, which was producing 1,500 megawatts of electricity.
• Colstrip Emissions: The flyover measured a massive carbon dioxide plume with concentrations over 100,000 parts per million, showing the Colstrip Plant in Montana was emitting 1.7 million pounds of CO2 per hour, equal to burning 4.4 railcars of coal.
• Visualizing Pollution: Aerial and satellite imagery, such as that from the Global Airborne Observatory and Carbon Mapper, provides a clear visual representation of pollution plumes that can be more impactful than numerical data alone.
• Carbon Mapper: This tool combines data from various sources—aircraft, its own satellite (Tanager-1), and NASA’s EMIT—to map and display greenhouse gas emissions for free.
• EPA vs. Satellite Data: Traditional EPA emissions reporting often relies on “inventory” calculations, which are based on the amount of fuel burned and an average emissions factor. This method can miss the hourly variations in emissions caused by differences in a plant’s efficiency. Satellite measurements, in contrast, offer more precise, real-time data.
• Largest U.S. Polluters: The largest emitters of CO2 in the U.S. are coal-burning power plants. The list of top polluters directly mirrors a map of regions still dependent on coal for electricity.
• Top 10 Emitters: The article lists the top 10 largest CO2 polluters in the U.S. as of August 2025, based on Carbon Mapper data. The top five are:
  1. Labadie Energy Center (Missouri)
  2. Coal Creek Power Station (North Dakota)
  3. Oak Grove Steam Electric Station (Texas)
  4. Jim Bridger Power Plant (Wyoming)
  5. Colstrip Generating Plant (Montana)