Total carbon awareness

It seems like one of those government reports that was finished, then stuck in a drawer somewhere. Sure, it’s a critical part of the county’s new climate-action plan. But since it was completed in June 2009, the public has mostly overlooked the 300-page Sacramento County Greenhouse Gas Emission Inventory, which is chock-full of specific data on Sacramento’s climate-change impact.

In all, Sacramento County residents, governments and businesses spew about 14 million metric tons of carbon dioxide equivalent, or MMTCO₂e, into the air every year. By comparison, the base-line greenhouse-gas pollution level for the state of California is about 487 million metric tons. And yet local governments like Sacramento are now tasked with tracking and reducing their contribution to the global greenhouse problem.

It shouldn’t surprise anyone that driving automobiles is the biggest source of greenhouse-gas pollution in the Sacramento area. About 6.7 million metric tons, or half of the CO₂ pollution in the region, comes from on-road transportation, which includes our cars and light trucks. It’s not just that we like to drive, it’s where we live that pushes the number up.

“Our land use dictates the number of miles everybody drives. Business as usual is not sustainable,” said Antonia Barry, with the county Department of Environmental Review and Assessment, who helped shepherd the report to completion.

The next biggest polluter is the residential sector. Heating and cooling our homes, keeping the lights on and the dishwasher running all contribute about 2.4 million metric tons of CO₂, or 17.5 percent of the load.

Commercial and industrial activity is close behind residential, accounting for another 16 percent, or 2.3 million metric tons. Methane gas from landfills around the county accounts for 5.3 percent of the total greenhouse-gas pollution. Off-road vehicles, including everything from farm equipment to jet skis to lawn mowers, are responsible for 4.2 percent. The Sacramento International Airport alone accounts for 1.4 percent of the county’s CO₂ burden.

The report gets even more granular. For example, the average household in Sacramento contributes about 10 metric tons of CO₂ into the atmosphere each year. It turns out that agricultural operations in the city of Isleton only account for 11 metric tons of CO₂ annually. Meanwhile, the use of natural gas in Elk Grove accounts for nearly 130,000 tons of CO₂ every year.

Powering county traffic lights contributes about 10,000 tons, while county workers commuting to and from work contribute about 2,000 metric tons to the CO₂ load.

Why bother keeping track of all this pollution? “We’re trying to set thresholds for each of those sectors,” Barry explained. And you can’t cap carbon-dioxide emissions without some sort of base line.

With a base line set, the county could set CO₂ targets for each sector. For example, before approving a residential development, the county may require a developer to lessen the impacts of residential subdivision by requiring mitigating measures, like bike lanes or Energy Star-certified appliances.

The county board of supervisors will meet next month to begin work on the next phase of Sacramento County’s climate-action plan. Phase one included the inventory and some broad principles. Now county planners are preparing detailed economic analysis and will craft a set of new measures aimed at curbing greenhouse gases. The state’s Global Warming Solutions Act, or Assembly Bill 32, includes policies aimed at reducing pollution in all of the sectors mentioned above. And the law calls on local governments to reduce greenhouse-gas emissions, too.

That law is under attack by business groups and out-of-state oil companies, such as Valero and Tesoro, which are spending millions to qualify a California ballot measure that would suspend the law.

For now, though, local governments are expected to take their own steps to curb greenhouse gases. That includes keeping track, locally, of global-warming pollution.