And yet the world caught a glimpse of a surprisingly greenminded Arnie last week, as he and UK prime minister Tony Blair signed an unusual UK-California partnership agreement to combat global warming.

With the oil refineries and loading docks of the port of Long Beach as a backdrop, the California governor and the British prime minister made common cause on developing scientific research and workable economic incentives to help save the planet.

The agreement was all the more remarkable because it marked a clear break between Schwarzenegger and his fellow Republicans in the Bush administration, who have steadfastly rejected overtures on addressing climate-change issues . . .from Blair and everyone else.

"There are many issues where I feel that California should lead the way, " Schwarzenegger said.

"The White House is not for it. But we are for it. The people of California are for it."

In many ways, this kind of talk is smart politics. It never does any harm to upstage a president, especially one whose approval ratings are tanking.

Schwarzenegger also faces reelection later this year, and he knows that Californians are markedly more concerned about the environment than Americans as a whole. An opinion poll published last week by the Public Policy Institute of California showed that eight out of 10 Californians believe global warming to be a serious threat to the future of the state's economy and quality of life.

But Schwarzenegger has a respectable record on the environment all round, signing bills and championing energy-saving initiatives that his Democratic predecessor, Gray Davis, would most likely have shunned.

His key environmental advisers are not former energy-industry lobbyists, like many of President Bush's appointees, but are long-standing green activists who came to Schwarzenegger via his wife, Maria Shriver, a member of the liberal Democrat Kennedy clan.

And so Governor Schwarzenegger has offered incentives to Californians to build solar energy panels on their roofs.

He has championed a switch to more renewable energy sources, pushed for cleaner car exhaust pipes and has said he is committed to imposing caps on how many greenhouse gases Californian businesses are allowed to produce.

What makes him very different from most Republicans is that he doesn't see an economic disadvantage to curbing global warming . . . on the contrary.

"He sees doing something on climate change as a potential economic driver for California, as well as a way to enhance his international credibility, " said Mark Bernstein, a senior policy researcher specialising in energy and environmental issues at the Rand Corporation.

"Imposing environmental regulations and cleaning up the air clearly hasn't hurt the Californian economy in the past. Now there's money to be made on developing technologies to reduce greenhouse gas emissions. California is where a lot of the research and development is going to take place."

Schwarzenegger hasn't given up his love of Hummers, just as he has no intention of giving up his beloved cigars. But he is interested in making Hummers, and other vehicles, more fuel-efficient.

He has said he's looking forward to driving a hydrogen fuel-cell powered Hummer, and has talked about creating "hydrogen highways" up and down the Golden State . . . a whole new fuel infrastructure that would one day replace petrol stations.

Politics aside, California has very concrete reasons to fear the consequences of global warming.

Higher temperatures would automatically put a crimp on the state's most precious resource . . . water . . .

which in turn would affect everything from agriculture to industry to housing development.

One recent estimate suggests the wine-growing areas of the Napa and Sonoma valleys could see their output shrivelled by as much as 80% over the next hundred years.

A report put out by California's Environmental Protection Agency to coincide with Blair's visit painted a grim picture of parched, stifling cities over the next few decades, as well as the prospect of 90% of the snowpack from the Sierra Nevada mountains . . . a crucial water source . . . melting by the end of the century.

Schwarzenegger is not without his critics. Democratic leaders in the state legislature are currently accusing him of trying to water down legislation now under discussion on greenhouse gas emissions, because of his ties to big business. Some environmental lobbyists worry that the agreement with Tony Blair is no more than window-dressing because it is entirely non-binding. Hydrogen, meanwhile, has many critics who believe it is both unworkable as an alternative to gasoline and still damaging to the environment because it is extracted from natural gas.

Schwarzenegger nevertheless appears to have stolen a march on Phil Angelides, his Democratic challenger for the governorship this November.

"What he's doing is taking a major campaign issue off the table, " Bernstein said. "It's going to be very difficult for Angelides to differentiate himself."