As we start writing the code for the new zoning ordinance, a “big picture” view seems in order. The biggest-picture formula in climate change, called the Kaya identity, is:

F=Pgef

F = Global CO2 emissions (combustion, flaring of natural gas, cement production, oxidation of nonfuel hydrocarbons, and transport) P = Global population (total number of human beings) g = Consumption per person (gross world product divided by population) e = Energy intensity of gross world product (global energy consumption divided by gross world product) f = Carbon used to make energy (global carbon dioxide emissions divided by global energy consumption)

The most obvious thing about this equation – if you remember even grade-school math – is … Continue reading