ALL the best first footers come with a lump of coal. For his debut on Sunday with Laura Kuenssberg, Myles Allen turned up with two.

The Oxford climate change professor had a story to tell about global heating, and he needed some props to do it. So he held up one chunk of the black stuff and said it represented a half trillion tonnes of fossil carbon. “If you burn it and dump all the CO2 into the atmosphere that represents one degree of warming,” he said. “When we first discovered we needed to reach net zero 15 years ago we had just burned through the first half trillion tonnes. It took 250 years.”

Then Prof Allen pickled up his second lump of coal. “Fifteen years later we are one-third of the way through the next half trillion tonnes, burning it as fast as ever,” he added. “And that one will take us to two degrees.”

That is a big deal, the scientist explained. Because the world has decided that it needs to keep global heating to a degree and a half to avoid the worst of predicted disasters.

The expert was on the show because the latest round of climate talks, COP27, is kicking off in the Red Sea resort of Sharm Al Sheikh. Much of the conversation will be around how the planet weans itself off carbon, how it switches to clean energy and how the rich world helps the poor one to do so.

But Prof Allen – not uncontroversially – thinks we have to find a way to reduce the harm from the oil, gas and coal we burn now. So he backs carbon capture schemes, which he claims are affordable.

Still clutching his coal, he told Ms Kuenssberg: “What I want politicians to acknowledge is that we have to stop fossil fuels from causing global warming before the world stops using fossil fuels.”

A well-prepared soundbite. But Kuenssberg wanted more: surely we have to kick our addiction to fossil fuels, she put to him. “It would be great if we could just say no,” he answered. “But fossil abstinence isn’t working.” Energy firms were ‘fly-tipping’ but this was a fixable problem.

Earlier in the show former Labour leader Ed Miliband, now shadow secretary for climate change, was keener on renewables. “It is now cheaper to save the planet than to destroy it,” he pointed out with another well-worn but increasingly undeniable buzz phrase.

Mr Miliband reckons his Tory opponents have lost a sense of urgency since they hosted the COP26 summit in Glasgow. “There is a vacuum of leadership,” he said (though he made clear he had time for Alok Sharma, the Conservative MP who is the outgoing president of COP).

The latest prime minister - at the time The Herald went to press this was a fella named Rishi Sunak - is headed to Egypt. He initially said he would give the event a pass.

Mr Sunak’s talking head on the Sunday morning shows was Oliver Dowden, the chancellor of the Duchy of Lancaster which, we were told, is a posh name for government “fixer”.

The poor guy had to explain why on Earth his boss gave a cabinet job to Gavin Williamson (the apparently yobbish “minister without portfolio” threw a four-letter text tiff when he did not get a seat at the Queen’s funeral).

Mr Dowden also had to stumble through an explanation for why Mr Sunak had changed his mind about going to Sharm. It is because the PM made “good progress on the autumn statement last weekend” and now has the time. The government is “strongly committed” to climate action, he insisted.

Over on BBC Scotland’s Sunday Show, Tessa Khan was not so sure. The green activist and lawyer told host Martin Geissler that British ministers were failing to live up to pledges made in Glasgow a year ago. “What matters is what leaders do when they come home,” she said. “The UK continues to disappoint.”

Nicola Sturgeon is also heading to Egypt, partly to push for aid to help poorer nations handle the unavoidable effects of climate change. But she did not escape criticism from Ms Khan, especially over the SNP’s need for North Sea hydrocarbons to bankroll their hypothetical independent state.

Scotland, of course, will only be sovereign if its people vote for it. And that means a referendum. Sir Keir Starmer, on the same programme, was having none of that.

Mr Geissler asked the Labour leader if Scotland was in a voluntary union (yes, he replied, it was). But what is the democratic mechanism would be for testing this? Are Scots “stuck” in the union?

“Of course they're not stuck,” he said “But this is about priorities. What is the priority at the moment? The priority at the moment is people paying their bills, is growing the economy.”

Mr Geissler had no luck getting any kind of answer on how Labour would respect the priorities of the Scottish electorate if they do not happen to coincide with his own. He might as well have asked one of Professor Allen’s lumps of coal.

Read more by David Leask:

Scotland's green energy revolution threatened by lack of planners

Scotland beware – polarised politics can mean terrible politicians