Vice Pres. Al Gore is marking Earth Day today with a trip to Shenandoah National Park in Virginia to announce a new plan that aims to clean up the air in national parks and wilderness areas to pre-industrial-era quality. New regulations will direct states to make notable air quality improvements every 10 years with a final deadline of 2064, which industry complains is far too soon. Old coal-fired power plants will bear much of the economic brunt, but new regulations are expected to ease the burden by enlarging an emissions permit trading system.