This story was originally published by Mother Jones and is reproduced here as part of the Climate Desk collaboration.

Could promises by Hillary Clinton and Bernie Sanders to dramatically restrict fracking actually make climate change worse?

In Sunday night’s presidential debate, both Democratic candidates came out swinging against the controversial technique for extracting oil and natural gas. Sanders was blunt. “No, I do not support fracking,” he said. Clinton was a bit less direct. She said that she would hold fracking operations to such high standards that “by the time we get through all of my conditions, I do not think there will be many places in America where fracking will continue to take place.” (You can watch their responses above.)