Gas leaks are huge trouble. Leaky pipes are not only prone to exploding (which is already terrible, of course), they also spew out methane -- a greenhouse gas more potent than carbon dioxide in contributing to climate change. The bad news is, nobody's been monitoring gas leaks closely, so Google Earth Outreach and the Environmental Defense Fund teamed up to do the job back in July. Now, the results for the project's pilot tests are out, and they confirm what everyone suspects: old gas pipes do leak a lot more than new ones. In order to effectively survey large areas, the pair attached methane-detecting sensors to Google's famous roving vehicles: Street View cars. They then sent these dual-purpose vehicles to Boston, Indianapolis and Staten Island, whose results you can see in the images after the break.