The City's Office of Sustainability has released the first ever inventory of NYC's carbon emissions (PDF), which in the baseline year of 2005, was 58.3 million metric tons of CO2 equivalent. The three main sources by use were Heating, Electric and Combustion vehicles. If unchecked, Carbon Emissions are expected to increase dramatically to 73.9 million metric tons of carbon equivalent by 2030.

The report also breaks down the carbon emissions by sector (Residential, Commercial, Vehicles) and source (Electricity, Gasoline, Natural Gas, Heating Fuel Oil).

I've just started reading though the report, but already I find it a compelling analysis of a specific geography's contribution to global warming. It has significant limitations of scope though. It does not account for the goods produced for NYC, in particular the food produced to feed residents, virtually none of which is produced within the 5 boroughs. It would be a great next step to estimate the impact of the manufacturing and agricultural sectors that support the city.

There is a section that includes aviation and shipping into the estimates of NYC's carbon emissions, but they do not include that in the grand total for the City, but recognize that they are something the city does have control over.

One point the report makes very clear is how New York is already far ahead of other American cities because of its dense multi-unit living spaces, its walkability and high rate of mass transit ridership. New York emits only 1/3 the carbon per capita as the average American. This shows the absolute advantage of urban areas over the suburbs in greenhouse gas emissions.

Now that the City has captured this data, it should continue to track this over time and include this in the City's performance reports. For policy makers this should put added pressure to increase efforts to promote green buildings and alternative modes of transportation.