San Francisco just passed a carbon tax.

In six weeks, more than 2,000 businesses in the nine Bay Area counties will pay $0.044 per ton of carbon dioxide they emit. We're talking about supermarkets, gas stations and many other types of businesses.

That's considered way out on the cutting edge, attacking a global warming gas at such a local level.

It's not the City Council or the Board of Supervisors doing it. The new law comes from the Bay Area Air Quality Management District -- the Bay Area's version of the San Joaquin Valley Air Pollution Control District.

Close vote? No way. It was 15-1.

The Bay Area district will get about $1.1 million each year and will use it to fund the collecting and tracking of greenhouse gas emissions.

How many other air districts will follow? Should the Valley be one of them?