One of the base-line metrics going forward. Be it county, state, national, or global. Keeping an envelope (and noting the annoncement that UK greenhouse gas emissions were down 7% in 2011! in the news this week-end). It's a baby-steps path forward. Can we do better in our urban systems by integrated monitoring and management infrastructures. With Individuals being aware of their aggregated footprints. The Urban Dome idea from Picarro is part of that envelope - emissions related to people, working personal and group actions, in their life choices and social context fills out the middle.