"A lot of this stuff might be put on the far back burner for a while," Martinson acknowledged.
California's municipalities, in fact, aren't seen as "agents of reduction" under the state's framework. There's no emissions bar under which cities must slip by a certain date.
"We are looking to forward-thinking municipalities to come up with innovative solutions," said Stanley Young, spokesman for the California Air Resources Board's climate programs.
"They're more nimble, certainly, than the state. In a sense they're able to be the test bed for these new approaches."
But at this point, he said, "it's all voluntary."
Nuts and bolts of emissions cuts
Still, cities are laying an important foundation that must be in place regardless of the target ultimately set by global leaders: They're figuring out the nuts and bolts of how to cut emissions.
"Demand-side reduction requires sophisticated implementation. It needs to show up at the local level and show up for the end-user," said Steve Pomerance, the former Boulder City Councilman who helped write Boulder's carbon tax earlier in the decade.
It's no surprise that Boulder would take the lead here.
The city is affluent - near the top 10 percent in the United States in per-capita income, according to the U.S. Census Bureau - and brainy. The University of Colorado, the National Center for Atmospheric Research and several other research institutions make the city a hub for science and innovation, repeatedly propelling the city to the top of Forbes' annual list of America's smartest cities. (link: http://www.digitaljournal.com/article/250167)
It's also a green city, with a network of dedicated bike and hiking trails and the nation's oldest open-space program hemming development. Trails, sun, snow and mountains draw a young, outdoorsy demographic that boasts one of the most liberal voting records in the West.
In 1982 the city limited building heights that shaded lots to the north to preserve solar access on the neighboring lot. In 1987, long before most city councils had heard of global warming, the city reassessed its water plan to account for lower runoff expected in a warmer climate. It bought a crucial upstream reservoir to secure extra storage.
In 2002, with the Bush Administration stalling, Boulder decided it would meet the Kyoto protocol, and the council quickly concluded it needed a way to pay for the necessary climate change programs. Many argued for a fee, which didn't require voter approval.
Pomerance, a key player in both the solar shading law and the reservoir purchase, pushed for a tax. "Go to the voters. Say straight out here's what you want to do," Pomerance said in an interview. "That way you have a mandate. (Otherwise) you're always swimming upstream politically."
In 2006, 60 percent of Boulder's voters approved the tax.
And the city discovered the hard work had just begun.
The tax is modest - $11 a year tacked to a typical household's energy bill. This summer the council raised the levy to its maximum, $21 per year for the average household. It will bring in $1.8 million next year.
The city offered home energy audits. It pushed biofuels and rooftop solar. It discounted energy-efficient lighting, furnaces and insulation. And six years in, the city found emissions have grown instead of shrunk.
That's the true difficulty in solving climate change, Pomerance says: World leaders can agree on targets. They can agree on a cap. But then what?
"That's just the first eighth-inch on top of a 10-foot pile of work. There's all these other pieces that have to go along with it," Pomerance said. "I'm a local politico. All I'm looking at is the implementation - 'OK, that's fine, now what do we do?' "
San Diego has taken a whack at that question, too.
Eighteen months ago a coalition of environmental groups, utilities, and government agencies decided to combine their various conservation and efficiency campaigns into one umbrella marketing effort - Stand for Less.
Nowhere on the campaign's website or advertising materials are the words "global warming" or "greenhouse gas emissions." Instead, the focus is on using less, recycling more, saving water, consolidating errands.
The goal, said Mark Oldfield, a spokesman for the state's Department of Conservation, which is coordinating the effort, is to see whether by tackling these very concrete efforts, a more abstract goal - California's climate change objectives - can be achieved.
"It's a very simple metric," Oldfield said. "We didn't want to make it brain surgery. We wanted to look at it and see clear-cut numbers."