Blame rising gas prices, Hugo Chavez's strident antics or Al Gore's Powerpoint slides -- energy and climate change issues have earned a prominent place in the race for the White House.

The main Democratic contenders -- Senators Hillary Clinton and Barack Obama -- boast detailed agendas in their campaign websites on how they would deal with the energy crunch and the global warming challenge.

The stance of both candidates seems drawn with the same pen, however. Both say they want to reduce greenhouse gas emissions by 80 percent below 1990 levels by 2050. Both support a market-based cap and trade system to achieve that goal; and both want 25 percent of U.S. electricity to come from renewable sources by 2025. They both also want to spend $150 billion over the the next 10 years on clean energy.

The differences are minute. Clinton proposes to put a third of that $150 billion in a strategic energy fund partly paid for by oil companies. Obama proposes a 'green jobs corps' to connect lower-income people with environmentally friendly jobs. You can see the detailed lists at Obama's and Clinton's websites.

The campaign site of the presumptive Republican candidate, John McCain, is a lot less specific about what regulatory paths to take, but shares the same alarm about climate change. Global warming, he says, is "an issue we can no longer afford to ignore."

He proposes a "common-sense" approach to limiting carbon emissions by "harnessing market forces" that will speed up access to advanced technologies "such as nuclear energy" and reduce U.S. dependence on foreign oil and gas.