For those going to tonight's meeting on the transit-oriented communities bill: An exhaustive new report (via Sightline) shows that carbon emissions for people who live in dense cities are far lower than those who live in suburbs. And the denser a city is, the less carbon each of its inhabitants emits. Why? Because people who live in cities drive less (producing lower transportation emissions) and use less energy overall (because sharing walls reduces energy consumption). Just something to keep in your pocket when the pitchfork crew starts shouting that density is bad for the environment.