March 21 (Bloomberg) -- John McCain is so passionate about global warming that he talks about it at some campaign events before bringing up Iraq.

The presumptive Republican presidential nominee's embrace of the issue obscures what many activists charge is an inconvenient truth: his weak overall environmental record.

``To his credit, McCain has made global warming a priority,'' said Gene Karpinski, president of the Washington- based League of Conservation Voters. Still, ``throughout his time in Congress, McCain's voted pro-environment only one out of four times.''

Karpinski and other environmentalists criticize McCain's positions on renewable energy, livestock-grazing practices, timber sales and funding to conserve public lands, wildlife and oceans.

In his quarter-century in Congress, McCain has demonstrated a ``pattern of voting with polluters and special interests instead of consumers and the planet,'' said Carl Pope, executive director of the San Francisco-based Sierra Club.

McCain antagonized environmentalists by voting in 2006 to open 8 million acres in the Gulf of Mexico to oil drilling. In addition, they have clashed over McCain's support for multibillion-dollar subsidies to the nuclear industry.

Renewable Energy

He was also criticized for backing conventional uses of coal while opposing requirements for electric utilities to get more of their power from renewable energy sources.

Separately, the Arizona senator has been taken to task for his support of President George W. Bush's 2007 budget, which cut funding for conservation programs by more than $3 billion, or 10 percent.

McCain rejected the criticism.

``I'm very proud of my environmental record,'' he said in a March 12 interview.

He pointed to the Teddy Roosevelt ``Environmental Hero'' award he received from Republicans for Environmental Protection and the praise he has received from the Grand Canyon Trust, a conservation group in Flagstaff, Arizona.

Former Arizona Governor Bruce Babbitt, a Democrat who was interior secretary in President Bill Clinton's administration, agreed with that assessment.

Grand Canyon

``McCain's been a strong and consistent friend on Grand Canyon issues -- river, air quality, noise,'' Babbitt said, though he wouldn't rate McCain's overall environmental record.

Jim DiPeso, policy director of Republicans for Environmental Protection, based in Albuquerque, New Mexico, said McCain isn't getting his due.

``It's not easy to stand up in the Republican Party and talk about global warming because people will say you've drunk Al Gore's Kool-Aid,'' he said.

Environmentalists agree that McCain has been a leader on global warming in his party. Yet they said his plan to cap greenhouse gases doesn't go as far as proposals from Democratic presidential candidates, Senators Hillary Clinton of New York and Barack Obama of Illinois.

``His proposal now falls far short of what the science says is needed,'' Karpinski said.

Environmentalists also said McCain, 71, is a relatively late convert to the global-warming bandwagon.

`Don't Know Anything'

In 2000, when he first ran for president, he said, ``I didn't know anything about climate change.'' Upon returning to the Senate, he delved into the issue and quickly championed the cause.

In 2003, he co-sponsored a proposal with Connecticut Independent Senator Joe Lieberman, then a Democrat, to cap the emissions of carbon dioxide that died in the Senate.

Two years later, another version of their plan also failed, in part because some environmental groups opposed the nuclear subsidies it contained.

Since then, McCain has continued touting the need to curb emissions.

``I believe it's a threat to our very existence,'' McCain said at a March 12 town hall meeting in Exeter, New Hampshire. Reversing global warming, he said, will prevent climate change and help end U.S. dependence on foreign oil.

Those views won McCain votes from independents as well as Republicans in the Jan. 8 New Hampshire primary, said Ted Leach, co-chairman of the Clean Air-Cool Planet Coalition, based in Portsmouth, New Hampshire.

Earth Day

McCain also is citing his global-warming stance to counter Democratic contentions that his presidency would amount to a third Bush term. He is finalizing plans to speak at this year's Earth Day celebrations on the National Mall in April, according to event organizers.

McCain gets low ratings from environmental groups, which many Republicans say are biased toward Democrats. This year, the League of Conservation Voters, with input from 18 other environmental-advocacy groups, gave Clinton, 60, a lifetime Senate rating of 87 percent and Obama, 46, an 86 percent rating. McCain got 24 percent.

``People can easily be fooled by the fact that McCain's taken a fairly good position on one aspect of global warming but has actually taken fairly bad positions on many other aspects,'' Pope said.

On global warming, McCain, Obama and Clinton all support a mandatory cap-and-trade system to reduce carbon-dioxide emissions. Clinton and Obama would reduce such gases by 80 percent by 2050. McCain's plan would reduce the emissions by 65 percent.

``McCain has spoken consistently on behalf of environmental protection,'' Pope said. ``Yet he has voted in a way that doesn't back his words.''

To contact the reporter on this story: Edwin Chen in Washington, at echen32@bloomberg.net

Last Updated: March 21, 2008 00:01 EDT