Natural gas is composed mostly of climate-warming methane but also contains other gases such as hydrogen sulfide, which is deadly at high concentrations. Gas escapes as wells are drilled and before infrastructure is in place to capture it. It also can be intentionally released if pressure in the system poses a safety risk or if capturing and transporting it to be sold is not profitable. Typically, drillers burn the gas they don’t capture, converting the methane to carbon dioxide, a less potent greenhouse gas, in a process called flaring. Sometimes, they release the gas without burning it, in a process called venting.

The permit applications showed oil companies requested to flare or vent more than 195 billion cubic feet of natural gas per year, enough to power more than 3 million homes and generate millions of dollars of tax revenue had the gas been captured. Those emissions would have a climate-warming impact roughly equivalent to 27 gas-fired power plants operating year-round, even if the flares burned every molecule of methane released from the wells.