Democratic front-runner Hillary Clinton pledged to slash US greenhouse gas emissions, as she aimed to bounce back from her most difficult week yet on the campaign trail.
Clinton's comprehensive plan to tackle global warming represented the latest sign that environmental issues are playing a greater role in the 2008 White House race, than in any previous US election.
"This is the biggest challenge we've faced in a generation, a challenge to our economy, our security, our health, and our planet," Clinton said yesterday in the midwestern state of Iowa, which holds first party nominating contests on January 3.
"It is time for America to meet it," she said.
The Clinton plan uses a cap and trade system to reduce greenhouse gas emissions by 80 per cent from 1990 levels by 2050, in a bid to head off the most damaging results of global warming.
It also sets a target of reducing foreign oil imports to the gas guzzling United States by two-thirds from levels projected to be reached in 2030 -- a cut of 10 million barrels per day.
The plan is also designed to kick-start research and development on clean and energy efficient technology and to cut energy consumption in the home.
Clinton would also increase fuel efficiency standards to 55 miles per gallon over the next 23 years, and help US car manufacturing giants retool production plants with USD 20 billion in "green vehicle bonds.