For the left, climate change is a godsend. It’s the ultimate silver bullet for a movement who have lost just about every economic argument for thirty-five years.

You want to wildly overregulate individuals and business? You want to raise taxes on individuals and on business? You want to reduce individual freedom and curb people’s opportunities to enjoy the fruits of their labour? Class war rhetoric, socialist ideology and bankrupt economic theories don’t persuade the electorate any more. But if you’re saving the world – well, if it’s true then that’s different. Who doesn’t want the world to be saved? Go ahead. Hell, take my (hybrid) car.

No doubt there are real greenies out there who simply and wholeheartedly believe that only by shutting down factories, pricing the poor out of lighting their homes and outsourcing jobs to China can we prevent the apocalypse. But they work among a horde of watermelons – the “green on the outside, red on the inside” people for whom Day After Tomorrow-style claims are simply a fantastic excuse to do things they want to do regardless, but weren’t previously allowed to.

Exposing such deceit is yet another way in which shale gas is a 21st century boon. The development of a new energy source is a great thing in and of itself, but it also allows us to start sifting out the real greens from the watermelons who use the argument as cover.

We know that shale gas offers new economic benefits, and a boost to energy security, but those considerations are often pooh-poohed by those who cite the prevention of global annihilation as the main policy objective.

What they neglect are the environmental benefits of shale gas. No less a body than the UN IPCC, the green movement’s college of cardinals (with less black smoke), has confirmed what shale fans have long argued – gas emits far less CO2 and fewer polluting particulants than coal, and a shift to fracking is therefore a good thing in green terms.

So here’s the challenge for our green friends. If you genuinely believe that reducing CO2 emissions is essential above all other things, will you support the development of shale gas in the UK?

Those who do will reveal themselves at least to be consistent with their claimed principles. The rest, who continue opposing shale gas in defiance of the facts, will be fully deserving of the name watermelon.