The majority of methane emissions from the U.S. oil and gas industry can be attributed to a surprisingly small number of sources along its supply chain, according to a new study published by researchers this week.

“From the synthesis of 18 studies and over 15,000 individual measurements, we were able to identify a consistent finding from them," said Garvin Heath, a senior scientist with the National Renewable Energy Lab, and a co-author on the study.

The consistent finding was that 5 percent of sources are responsible for more than 50 percent of total volume of methane leaks. 

Natural gas is viewed as a cleaner burning fuel compared to coal. But scientists in recent years have found that wells and production facilities leak methane. It's a greenhouse gas that traps 30 times more heat in the atmosphere than carbon dioxide.

The study was published in the journal Environmental Science & Technology.