Dense urban areas as "green" in the sense of having a smaller carbon footprint for a variety of reasons, but the concentration of emissions is bad locally. And it's the
damn cars.
Researchers at UCLA's Institute of the Environment and Sustainability found that air quality near 405, when it was closed, was 83 percent better than during a typical weekend. What's even more amazing is that Carmageddon, in just two days, made the air cleaner in surrounding regions. Parts of West Los Angeles and Santa Monica saw air quality improve by as much as 75 percent.
