LOS ANGELES, April 25 (Xinhua) -- California Governor Arnold Schwarzenegger warned Wednesday that the state would sue the U.S. Environmental Protection Agency (EPA) if it fails to act on a request to reduce emissions.

    Schwarzenegger notified the EPA of California's intent to sue if the federal government fails to act on California's request for a federal Clean Air Act waiver that would allow it to regulate auto emissions more aggressively.

    In a letter, the governor sent a notice of intent to sue which is required six months in advance of any lawsuit to be filed.

    The governor also spoke with EPA Administrator Stephen Johnson by phone. The EPA has taken preliminary steps to act on California's waiver.

    "I have called on the federal government to expedite California's request, and now with a Supreme Court decision behind us, the time to act is now. If the federal government once again fails to act, we have an obligation to take legal action," said Schwarzenegger.

    "Californians clearly want to protect our environment. The U.S.EPA must act aggressively to grant our waiver so we can begin reducing greenhouse gas emissions."

    Earlier this month, the U.S. Supreme Court issued a ruling, saying the EPA has the authority to regulate greenhouse gases.

    By not acting, the EPA is preventing the rights of California and other states from taking action to reduce greenhouse gases. Eleven other states have adopted the California standards as their own and two more are now in the process. The group of states makesup about one-third of all U.S. auto sales.

    Under the federal Clean Air Act, California has the right to set its own vehicle emission standards, and other states have the right to adopt the California standards as their own.

    The 11 other states that have adopted California's vehicle emissions standards include: Vermont, New York, New Jersey, Massachusetts, Connecticut, Maine, Rhode Island, Pennsylvania, Maryland, Washington and Oregon. New Mexico and Arizona are in the process of adopting California's standards.

    On Dec. 21, 2005, the California Air Resources Board (ARB) requested a waiver of federal preemption of California's Greenhouse Gas Emissions Standards. The waiver would allow California to enact emissions standards to reduce carbon dioxide and other greenhouse gas emissions from automobiles.

    The waiver was requested after the ARB developed regulations based on the 2002 California law. In addition to the waiver being stalled in the federal process, the law faces a legal challenge by automakers.

    In letters sent on April 10, 2006 and Oct. 24, 2006 to President George W. Bush, the governor reiterated the urgency of approving California's request to address global warming.