Tallgrass Energy Partners, a midstream oil and natural gas pipeline company founded in 2013 and presently operating approximately 7,539 miles of pipeline in the U.S. states of Nebraska, Kansas, Wyoming, Colorado, Missouri, Illinois, Indiana, and Ohio, will begin monitoring emissions, including methane and other greenhouse gases, on its Rockies Express Pipeline, making it the first U.S. company to measure and certify the environmental impact of operations on an interstate natural gas pipeline. The Rockies Express Pipeline transports up to 4.4 billion cubic feet per day of gas between northwestern Colorado and eastern Ohio.

Natural gas producers, transporters and utilities are embracing carbon-reduction measures and third-party ratings to show investors and customers they are serious about reducing greenhouse gas emissions amid concerns over their environmental impact, much more than the critique of activist Greta Thunberg this week at a climate conference in Berlin.

Natural gas certification has been picking up steam in the past year among producers and utilities. Project Canary counts EQT Corp and LNG-project developer NextDecade among its customers. MiQ, another firm that applies measurements to help manage carbon emissions, has signed Exxon Mobil and Chesapeake Energy Corp to use its methodologies.

"This has been a missing link," said Project Canary CEO Chris Romer, of pipeline operators' role in emissions reduction. It is holding talks with more than a dozen other pipelines looking to monitor and certify the emissions footprint of their operations, he said.

The Colorado School of Mines will partner with Project Canary for the certification process.