FACTBOX: Presidential candidates on energy issues

(Reuters) - Energy and environment issues have gained prominence in the 2008 U.S. presidential contest as crude oil prices near a record $120 a barrel.

Here is what the candidates are saying about energy and the environment:

* CLIMATE CHANGE

New York Sen. Hillary Clinton, Democrat - Cut U.S. greenhouse gas emissions to 80 percent below 1990 levels by 2050 through cap-and-trade system; require all publicly traded U.S. companies to file report on climate change risks with the Securities and Exchange Commission.

Illinois Sen. Barack Obama, Democrat - Cut carbon dioxide (CO2) emissions to 80 percent below 1990 levels by 2050; reduce emissions to 1990 levels by 2020; require fuel suppliers to cut carbon content by 10 percent by 2020.

Arizona Sen. John McCain, Republican - Favors cap-and-trade CO2 approach; sponsored legislation in 2007 to cut emissions by 30 percent by 2050.

* GASOLINE PRICES

Clinton - investigate oil companies and energy traders to see if market manipulation is occurring; take pressure off pump prices by releasing emergency crude oil stockpiles; suspend 18.4-cents-per-gallon federal tax on gasoline during the summer.

Obama - probe energy industry activities, stop filling emergency oil reserve.