Retrofitting homes and buildings to reduce greenhouse gas emissions is a big but necessary task for Northeast and Mid-Atlantic States and cities committed to climate stabilization goals.

Natural gas creates carbon dioxide when we burn it to heat buildings and water. But it also leaks methane, an even more potent greenhouse gas, into the atmosphere when it does not make it all the way to our furnaces and water heaters. Older natural gas lines are more likely to leak. Sometimes the leaks get to explosive levels and make the evening news, but on a regular basis there are smaller leaks that emit methane into the atmosphere and contribute to climate change.