John McCain boards his campaign plane in Phoenix, Arizona, 23 Jun 2008

U.S. Republican presidential hopeful John McCain has outlined his latest proposals to fight global warming and reduce American dependence on foreign oil.

In a town hall meeting Monday in Fresno, California, Senator McCain called on auto manufacturers to speed up the process of converting engines to use alcohol-based fuels.  He proposed a $5,000 tax credit for each consumer who buys a zero-emissions car, and higher fines for automakers who evade existing fuel-efficiency standards.

Questioned by an audience member about nuclear power, he said the United States has to have it in order to reduce greenhouse gases.

Senator Barack Obama in Miami, 21 Jun 2008

On Sunday, Obama proposed a clampdown on energy speculation, which he says is largely responsible for record-high oil prices.  His proposal would close a legal provision that exempts energy commodities from government oversight.

Obama's proposal would close a legal provision that exempts energy commodities from government oversight.

Critics say the deregulation measure, signed in 2000 by then-President Bill Clinton, opened the way to uncontrolled speculation in the oil markets.

The high price of gasoline in the United States is a prominent campaign issue.  McCain wants Congress to lift a ban on offshore oil drilling to help ease the costs, while Obama says such a measure would not help the problem in the short term.

Some information for this report was provided by AP and Reuters.