Much of our thinking about the built environment is focused on individual buildings, which is generally a useful framework. Buildings align with ownership, buildings are regulated by zoning and codes, buildings frequently represent a utility customer, and buildings typically have their own heating and cooling systems. But many of the services that buildings receive are developed as part of a broader infrastructure, such as community water and sewer plants, transportation networks, and electricity.
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.