Oil and Gas Fields in Montana and North Dakota Responsible for Majority of Increase in Global Ethane Levels, Study Shows

A recent study shows that one particular oil and gas field in the United States is responsible for the majority of the increase in the concentration of ethane in the atmosphere for the last ten years.

According to the study published in the journal Geophysical Research Letters, the Bakken Formation, a gas and oil field located in North Dakota and Montana is emitting about 250,000 tons of ethane every year, which is about 2 percent of total global ethane level.

"Two percent might not sound like a lot, but the emissions we observed in this single region are 10 to 100 times larger than reported in inventories. They directly impact air quality across North America. And they're sufficient to explain much of the global shift in ethane concentrations," said Eric Kort, assistant professor of climate and space sciences and engineering at University of Michigan, and first author of the study, said in a statement.

To determine how much ethane is being emitted in Bakken Formation, the researchers sample the air over the Bakken by flying in a NOAA Twin Otter aircraft. The airborne measurements reveal that 0.23 teragrams, or 250,000 tons, of ethane is being emitted by the Bakken Formation, which resulted to the cancelling out of half of the global ethane decline rate.

The increase in ethane emission in the Bakken Formation is said to be the result of the steep increase in the oil and gas industry caused by the development of hydraulic fracturing, or fracking, and horizontal drilling. According to the study, oil production in Bakken Formation has jumped by a factor of 3,500 between 2005 and 2014, while the gas production has increased by 180.

Ethane is being leaked out in the atmosphere through fossil fuel extraction, processing and distribution. Once in the atmosphere, Ethane reacts with sunlight and other molecules in the atmosphere to form ozone. Low-altitude ozone or surface ozone can cause respiratory problems, eye irritation and other ailments and damage crops. In addition to the dangers surface ozone have to humans, it can also cause a negative impact in the environment. Surface ozone is a greenhouse gas that is known to be the third largest contributor to human-based global warming following carbon dioxide and methane.

This findings is one of the most recent evidence that shale oil and gas production of the fossil fuel industry is one of the main contributor to climate change.