California's efforts to reduce greenhouse gases jumped forward this week following landmark rulings from the nation's high court upholding restrictions on carbon emissions from power plants and cars. Although they were major victories for the state, California still has a steep climb before actually limiting global warming gases from motor vehicles and out-of-state power plants. "It is part one of many steps," said California deputy attorney general Ken Alex of the Supreme Court's April 2 decisions. A key step will be getting the U.S. Environmental Protection Agency to set vehicle carbon pollution standards - the development of which could take years, he noted. The Supreme Court, on a 5-4 vote in Massachusetts v. EPA, held that the agency must regulate global warming gases under the federal Clean Air Act unless it can prove that greenhouse gases don't cause adverse impacts. In a separate ruling released the same day, the judges unanimously concluded that Duke Energy's power plant upgrades to run its units harder and longer must include pollution abatement equipment in accordance with the air act's New Source Review rule. In Environmental Defense v. Duke, the Supreme Court invalidated a ruling by the U.S. Court of Appeals for the Fourth Circuit that was in Duke's favor. The suit heads back to the lower court. "We continue to believe we have solid defenses against the government's claims and will show in the lower courts that our power plant projects were not subject to New Source Review," said Marc Manly, Duke's executive and chief legal officer. In spite of expecting ongoing legal and institutional challenges, both rulings were welcomed by backers of the state's effort to slash greenhouse gases from stationary and mobile sources. "We remain hopeful that the EPA will soon deter-mine, as California has, that vehicle greenhouse gases must be reduced," said Governor Arnold Schwarzenegger. For Michael Carboy, financial analyst with Signal Hill, the court's unprecedented ruling authorizing the regulation of CO2 "is the first concrete step toward a carbon tax or cap-and-trade programs." He added that the power plant ruling appears to pressure utilities to clean up existing plants. "As carbon becomes a quantifiable cost," he said, industry overall is expected to seek more efficient systems, creating a favorable trend for solar and wind energy and sellers of energy-efficiency systems and air pollution control equipment. The ruling on CO2 emission from cars created a two-fold victory for greenhouse gas reduction proponents. The U.S. EPA can no longer refuse to regulate carbon as a pollutant, and the court upheld the state's right to enact carbon standards stricter than the federal government's rules. That keeps intact California law enacted in 2002 requiring cuts in tailpipe emissions from vehicles. That law, AB 1493 by former Assemblymember Fran Pavley, is an element of evolving California pollution control and greenhouse gas emissions law. The Supreme Court decisions lead to ensuring that California reaches the 25 percent greenhouse gas reduction mandate by 2020 under AB 32, the carbon reduction law. Making way for AB 1493 implementation will not be easy, according to observers. The state must get a Clean Air Act waiver from the EPA. In addition, automakers' lawsuits against the state must be resolved. The suit pending in federal district court in Fresno was put on hold while Massachusetts v. EPA was pending (Circuit, Jan. 19, 2007). Deputy AG Alex said his office asked federal district judge Anthony Ishii this week to schedule a conference to set trial dates. The fate of that automobile manufacturers' suit challenging the tailpipe emissions law before Ishii was indirectly affected by an April 5 ruling in Vermont. Following the Supreme Court's ruling in Massachusetts v EPA, the Vermont court could have rejected the suit challenging the state of Vermont's regulations modeled after California's to limit car tailpipe emissions. Instead, the Vermont judge set the matter for trial. Other litigation involving state efforts to curb green-house gas emissions from generating units and vehicles also hangs in the balance. California joined with a group of seven states in a suit against five power companies considered the top emitters of carbon dioxide on nuisance grounds (Circuit, March 24, 2006). The AG also sued auto-makers for their cars' carbon emissions, and the case is in the federal district court in Oakland (Circuit, Feb. 9, 2007). Attorney General Jerry Brown's attempts to meet with automakers' top brass to try to resolve the latter deal have been unsuccessful.