Just back from a visit to the slightly scary cities of the American south-west – Phoenix and Tucson. Having just read an extraordinarily powerful novel called ‘The Water Knife’ by Paolo Bacigalupi (which is all about the western States, at some point in the not-too-distant future, when climate-induced drought has spurred war between California, Nevada and Arizona), I was gobsmacked to see how resorts, upmarket new housing and hotels are spreading right out into the surrounding desert, regardless, it would seem, of chronic water scarcity issues.

My reason for being there was to take part in the One Young World Environment Summit – the first such Summit that this wonderful organisation has brought together. I was talking about the power of innovation, and working together with Collectively, we organised a competition to identify two young environmental entrepreneurs to co-present during the same session.

I have to say they were both amazing. First up was Guro Grytli Seim, presenting the work that her company (One Earth Designs) is doing to promote a very exciting variation on the standard solar cookstove. She was followed by a young man (still 18!) called Leroy Mwasaru who has been transforming his own school and community in Kenya with new ways of treating human, animal and kitchen waste.

It was such a good event. Great presentations, lots of vibrant young voices, tempered with a few notionally wiser and definitely older hands!

Including the redoubtable Jan Pronk, veteran Dutch politician and one of the principal influencers behind the 1997 Kyoto Protocol on Climate Change. He was excoriating in his criticism of the shiny new Paris Agreement. Instead of seeing it as a really positive step forward (especially when compared with the nightmare of Copenhagen six years earlier), he characterised it as a ‘betrayal’, pointing the finger of blame at Barack Obama and others who he sees as giving up on any kind of binding legal instrument (as in the Kyoto Protocol), primarily at the behest of the fossil fuel companies and other carbon-intensive industries. I think people were a bit downcast by this!

There were also quite a few carbon-intensive companies on show at the Summit! Including GE, whose representative gave a wonderfully upbeat presentation around its Ecomagination business. The one case study she developed was a new cross-sectoral collaboration (involving other corporate giants including Total, still one of the world’s biggest oil and gas companies, but with an increasingly influential solar company) to bring a set of hybrid solar-gas solutions to the continent of Africa.

And there you have it! Most of the big carbon-intensive companies have now recognised that coal is dying, that oil is most likely on a downward trajectory, but that their saviour will be gas – for just as long as they can spin it out.

This is rapidly becoming the new campaigning and divesting front line. Should we be persuaded by the Totals of this world, belligerently banging their both/and drums (both gas and renewables), or should we be resisting such siren voices, and campaigning ever more resolutely to move towards a 100% renewable energy world just as fast as can possibly be achieved?

It may not be an entirely black and white answer here. If gas can be used to kill off coal in countries like China, India and Indonesia, that’s no bad thing in itself. If gas can be used in super-efficient power stations to produce both electricity and heat, then that may still have a role to play in big cities that urgently need to introduce domestic heating schemes.

But, and it’s a very big but, if any new investment in gas impedes directly or indirectly the transition to an ultra-low-carbon economy, locking us either into decades of hydrocarbon dependency or into the kind of financial chaos that will ensue when thousands of fossil fuel assets become stranded, then it’s clearly a zero-sum game.

And that’s what my good colleague, Jeremy Leggett, is now arguing. If he’d been there at the Environment Summit, he would have had very little time for Ecomagination’s plans for Africa – primarily on the grounds that gas is not the relatively clean fossil fuel that the industry would have us all believe.

“The industry repeats a mantra at every opportunity: that gas is less bad than coal in fuelling global warming, focussing on the fact that burning a unit of natural gas releases less greenhouse gas than burning a unit of coal. This is true, but ignores gas leakage. Gas leaks add methane, a potent greenhouse gas, to the atmosphere. If as little as 2% leaks before it is burned, gas is as bad as coal in global warming terms.

There is a growing body of evidence, across the entire global gas supply chain, of more than 2% leakage. Individual companies may be good at controlling their emissions, but their industry as a whole clearly fails the test. As long ago as 2011, scientists from Cornell University estimated that gas leakage from a US shale well could be 7.9% over its lifetime.”

And there are particular concerns around gas storage facilities, with most US gas, either fracked from shale or conventional gas, being stored underground in abandoned oil and gas fields.

“In October 2015, one such field near Los Angeles started to leak so profusely that it become California’s biggest source of methane emissions. When it was finally plugged, 112 days later, almost 100,000 tonnes of methane had escaped: the amount of gas consumed annually be a medium-sized European country.”

Jeremy Leggett’s warning is very clear. First, you really can’t trust any of the claims made by today’s oil and gas companies as to the advantages of gas. Second, whatever marketing greenwash they may deploy, they’re still using their formidable lobbying power (including their ability to ‘buy’ countless US politicians) as if the science of climate change didn’t exist. Third, we need to get used to a world without any fossil fuels just as fast as we can.

Speed is indeed of the essence, and, post-Paris, one really does begin to get the impression that the fossil fuel companies have at long last begun to see the writing on the wall. They don’t quite know what to do about it as yet, and many of them are now scurrying around in something resembling full-on panic, but it’s just not the same world they’re now operating in.

And the young and utterly inspiring delegates at the One Young World Summit were pretty clear that they expect this transition period to keep on moving faster and faster.