The folks at Global Green USA have come up with an easy way to tell how a city is doing on its carbon emissions: give it a grade.

That’s the idea behind Global Green’s City Carbon Index, an online tool unveiled late last month. It aims to measure a city’s emissions and helps to set benchmarks for improvement, as well as to inspire grassroots action.

City Carbon index

The organization’s president and CEO, Matt Petersen, explained the urban focus in a statement:

“More than 70% of CO2 emissions come from cities…. Cities offer an important opportunity for individuals and communities to create and support innovative solutions to global warming that also create green jobs, improve air quality and provide model solutions to reduce carbon emissions.”

The first city to get a City Carbon Index rating is Los Angeles. And clearly LA needs to do its homework better. It got a C- for its actions to reduce its carbon emissions, which are estimated at 52 million metric tons per year. Transportation is responsible for 24.8 million tons of that, and one of the first actions the site calls for is support of the city’s ambitious new bicycle plan.

It’ll be interesting to compare cities once more are added to the project. We’ll keep you posted.