The ecowarriors at Drax last week, assembled in a bid to shut down one of Britain’s most polluting power stations, must have been fairly bemused to know they had been joined in the global war against climate change by a jolly green giant.

Better known for pumping iron and kicking ass, Arnold Schwarzenegger is now lending his considerable weight to the environmental lobby. The governor of California has cut a deal with the Democrat-dominated state legislature on a Global Warming Solutions Act which aims to reduce emissions of greenhouse gases in the state by around a quarter by the year 2020.

It’s a move that has enraged his fellow Republicans and distanced him from his President, who still refuses to kowtow to the Kyoto Protocol.

So, why the lean to the green?

Has Arnie’s mighty arm been twisted by his über-Democrat wife, Maria Shriver, a member of the Kennedy clan? Or is he thinking of the bigger picture, attempting to achieve a David Cameron-style makeover of the Grand Old Party? Is he just trying to secure a second term in office for himself in the election later this year?

Or, maybe, as a world leader – after all, California’s annual turnover of $1.5 trillion places it among the world’s top 10 economies – he realises that a little star power could help to turn the tide when it comes to global warming.

Of course, he has his detractors. Many think he’s trying to please all the people all of the time. Yes, he helped to draft the global-warming Bill, but he seems also to have supported the oil companies in their defiance of legislation that would compel them to fund research into alternative sources of energy.

He hasn’t swapped his beloved Humvee yet for a Toyota Prius, but still it’s refreshing to see the Terminator discovering a new role as a true action hero.

And what about us? What part do we play? Many Christians in America are now seriously asking ‘What would Jesus drive?’ But is that enough? Perhaps not.

Many scientists concur that global warming would be inevitable even if we applied ‘best practice’ in our use (and conservation) of energy. All we can hope for now is to slow the rate of climate change.

Whatever Arnold Schwarzenegger’s motives, we can’t afford to ignore the fact that in the fight to save the planet we all have a crucial role.