How many more residents can the environment of United States support? That question hasn't been comprehensively studied, but there's a group that says that it should be.

Phil CafaroThe idea of a national study of the environmental impacts of population growth through immigration is not new, notes Phil Cafaro, president of Progressives for Immigration Reform and a Philosophy professor at Colorado State University. He's hoping that it's time is finally arriving.

It should be noted that there are those, including some respected civil rights organizations, who skeptically view Cafaro's organization as a front for deceptive political efforts to "greenwash" immigration politics.

The graph on the left, prepared by Cafaro, shows projected US population gains through the end of this century under four quite different immigration ceilings.

The two components of population growth are immigration and fertility, Cafaro, says, and in the United States' recent past, the two have been compounding.

The California Air Resources Board officials are calling the state's first-ever cap-and-trade carbon auction a success. And, as Lori Abbot reports, it could be an important milestone for California as a leader in the global clean tech market.

At right: A gasifier at Sierra Energy transforms waste into fuel. (Courtesy of Sierra Energy.)

The federal government (National Marine Fisheries Service) and wildlife conservation groups are aligned in in a battle over pesticide use, with the latest round in a Virginia courtroom. NMFS wants to require no-spray buffer zones around waterways where salmon and steelhead live and migrate, for certain chemicals that are toxic to the fish. The chemical manufacturers are challenging that rule. Reporter Lori Abbott outlines the arguments.

The U.S. Fish & Wildlife Service photo at the right shows fish casualties the agency says were the result of pesticide contamination. Courtesy of USFWS.

Halloween has special meaning for California's Death Valley, but it has nothing to do with spooks and spirits. Lori Abbot explains what the day's observance is really about.