According to a study from the University of Texas and published Monday by the Proceedings of the National Academy of Sciences, fracking well sites spew less of the greenhouse gas methane than previously thought.

First, a bit about methane.  The main component of natural gas, methane traps 21 times more heat in the atmosphere than carbon dioxide, according to the U.S. Environmental Protection Agency. However, when burned to produce electricity natural gas emits about half the carbon dioxide, the main greenhouse gas, as coal does.

If too much methane escapes through leaks, the environmental benefit of using it over coal is gone. The recent interest in hydraulic fracturing as a new source for America’s energy had opened a debate over whether expanding the use of gas would set back efforts to fight climate change.

The study sought to answer that question. Researchers took direct measurements over an entire year at 190 well sites in the Gulf Coast, Appalachian, Rocky Mountain and Great Plains regions.

The study found total leakage at the study sites during the extraction of natural gas from the ground was 0.42 percent of all produced gas, less than the EPA’s suggested total of 0.6-3.2 percent (the latter being the level that would erase the fuel’s climate benefit over coal.

Next, some disclosure about the study, which is not without some leaks of its own. About 90 percent of the study funding came from nine energy companies including the Houston-based Southwestern Energy Co. that drill for natural gas. It also was not a comprehensive study of all the places natural gas can leak. For example, additional leaks occur during the delivery from wells to homes and power plants.

Wenonah Hauter, executive director of Food & Water Watch, a Washington-based environmental group, said not enough wells were part of the study to “draw meaningful conclusions about national emissions.” Hauter went on to say that companies that allowed methane measurements at their wells most likely removed any sources of leaks before researchers arrived.

The study was, however, a collaborative effort between the energy companies and the Environmental Defense Fund, which works with companies to protect the Earth’s resources. The authors said they controlled how the research was done and how the wells were chosen for study. The companies were not involved in processing data captured at the well sites.

So the study has some flaws, but is probably one of the biggest steps toward better understanding methane leaks and their potential influence on climate change. Robert Howarth of Cornell University, one of the scientists who first called out the dangers of methane leaks says the results are “good news.”