There's no shortage of ideas on how to spend California's anticipated "cap and trade" billions.
But two recent reports lay out a compelling case for where a serious dose of that money, from the state's program to reduce greenhouse gas emissions, needs to go.
Last week, in an eye-opening map of communities most wracked by pollution, the California Environmental Protection Agency left no doubt that the Central Valley is by far the state's biggest and most vulnerable environmental challenge.
Color-coded from green to hazardous red to pinpoint areas with the greatest exposure to contaminated air, soil and water, the CalEnviroScreen map featured a big, crimson welt at the state's very core, festering from West Sacramento to Bakersfield.
The California EPA data looked at environmental risks and human demographics. By any measure, however, it was clear that the region's longstanding problems are shortening millions of lives.
In the worst tract, 3,000 men, women and children in West Fresno were breathing exhaust from three freeways, fumes from a rendering plant and a meat-processing plant, and tending fields that ranked in the 90th percentile for pesticide applications.
Conditions weren't much healthier in the surrounding counties, a point driven home by the second study, released Wednesday by the American Lung Association.
That report, which focused on levels of particulates and ozone, found that for the third year in a row, the Central Valley had the most polluted air in the nation, and that wasn't even counting the later months of last year, when air quality plummeted amid winter heat waves and drought.
Fresno, with its sooty air, had more particulates than any other American city, with Visalia-Porterville-Hanford and Bakersfield right behind it.
Certainly, the Central Valley's topography and climate pose a challenge. Surrounded by mountains, the region is a hot, massive sink that traps pollution and bakes it.
But more can surely be done about the man-made parts of its problems - the old fleets of farm equipment, the big-rig exhaust from Highway 99 and Interstate 5, the agribusiness pollution, the reliance on gas guzzlers.
Though California has so many electric vehicles now that the state has had to look at narrowing the requirements for the $2,500 rebates it offers, only 2 percent of those rebates have gone to owners of San Joaquin Valley cars.
The cap-and-trade fees California hopes to collect from factories, food processors, oil companies and other big polluters could make a difference. By law, a quarter of that money must go to "disadvantaged" communities.
As lawmakers debate grand plans, from high-speed rail to transit-oriented housing, they should keep in mind that the real bang for the buck will be in the geographic focus of these projects.
A pollution-steeped red zone with asthma rates that are triple the national average shouldn't be the future of our state.