The pipes that carry natural gas in major U.S. cities are often more than 100 years old and prone to corrosion and leaks. This contributes to not only safety concerns over potential explosions, but also environmental ones — methane released in these leaks is a potent greenhouse gas.
Starting in 2013 and funded by the Environmental Defense Fund, a fleet of Google Street View cars was fitted with high-precision methane analyzers. The cars map the locations of natural gas leaks, and measures their severity by taking in air through the front bumper and pumping it to a tube in the trunk, where its methane content is measured by a laser-based sensor. The system is continually taking air samples as the Google cars drive through neighborhoods, generating 2,000 data points per minute. By keeping track of where gas leaks are occurring, cities can better protect both citizens and air quality.