FACTBOX: U.S. presidential candidates on environment, energy

(Reuters) - With crude oil prices surging to record highs above $130 a barrel, energy and environmental issues like global warming have moved to the forefront of the U.S. presidential campaign.

Here is what Republican John McCain and Democrat Barack Obama, who claimed his party's nomination on Tuesday, are saying about energy and the environment:

CLIMATE CHANGE

Obama would cut carbon dioxide emissions to 80 percent below 1990 levels by 2050, reduce emissions to 1990 levels by 2020 and require fuel suppliers to cut carbon content by 10 percent by 2020.

McCain favors a cap-and-trade CO2 approach. He sponsored legislation in 2007 to cut emissions by 30 percent by 2050.

GASOLINE PRICES

Obama would probe energy industry activities and stop filling the emergency oil reserve.

McCain wants to suspend the federal gasoline tax during the peak summer driving season and suspend filling of the Strategic Petroleum Reserve, a stockpile designed to ensure the United States has a cushion of crude oil to cope with major supply disruptions.

(On May 19, President George W. Bush signed a law to temporarily halt shipments to the reserve, which now holds almost 703 million barrels at four underground storage sites, until crude prices drop below $75 a barrel.)

OIL USE

Obama would reduce overall U.S. oil consumption by at least 35 percent, or 10 million barrels per day, by 2030 to offset imports from OPEC nations.

McCain has set no specific targets. He has said he will unveil a strategy to reduce reliance on foreign oil sources.

VEHICLE FUEL ECONOMY

Obama would double fuel economy standards in 18 years, give automakers tax credits to retool plants and invest in advanced lightweight materials and new engines.

McCain has not specified Corporate Average Fuel Economy (CAFE) targets. He voted against energy amendments in 2003 that would have boosted CAFE to 40 mpg by 2015.

BIOFUELS