Cop26, states Boris Johnson, will mark “the turning point for humanity”.
The British prime minister may well be right, but the question remains: will history hail Glasgow as the place where humanity finally showed the resolve to tackle climate change?
When Britain is on the world stage next week it will certainly be hosting the most important global conference for years.
If success is measured in the number of world leaders attending, then 120-plus have agreed to travel to Glasgow, lured perhaps by Mr Johnson's bonhomie and the presence of 95-year-old Queen Elizabeth II, before she pulled out earlier this week.
But the royal family, the prime minister and the world’s abnormal weather patterns have not proven a draw for President Xi Jinping of China, whose country is considered the biggest global polluter. The same for President Vladimir Putin of Russia, although his dire relations with Britain might also be a reason.
The summit, however, should not be judged on a pageant of world leaders as every country, including China and Russia, is sending delegations with the authority to strike deals.
And success or failure will be measured on the basis of those deals.
The UK, which holds the UN’s Conference of the Parties (Cop) 26th presidency, will have to persuade all countries to make firm commitments that fix dates to curb emissions and give billions to poorer nations.
Mr Johnson said this week success at Cop26 remains "on a knife edge".
That is partly his way of dampening expectations and protecting his reputation, if it fails.
“We need as many people as possible to go to net zero so that they are not producing too much carbon dioxide by the middle of the century,” he said.
“Now, I think it can be done. It’s going to be very, very tough, this summit.
“And I’m very worried, because it might go wrong and we might not get the agreements that we need.
“It’s touch and go.”
On the flip side, if he pulls it off Mr Johnson's achievements will seem even more impressive. He hopes “peer pressure” at the UN summit could force some nations into action.
The acronym NDC will soon become familiar. Nationally Determined Contributions are the undertakings countries make to reduce their carbon emissions by a certain date.
Britain plans to drop them by 68 per cent by 2030, the European Union by 55 per cent in the same year. But many countries have yet to outline or submit their NDCs, China included.
Mr Johnson, well-rehearsed in hosting world leaders after fronting the G7 summit in Cornwall in June, will again welcome President Joe Biden. The US leader, unlike his predecessor Donald Trump, is among those firmly convinced that much needs to be done to reverse climate deterioration.
Snow storms in Texas, droughts in California and forest fires pretty much everywhere are among the main reasons. And that’s just America. Nearly every country is experiencing unusual weather events as the earth warms.
Observers point to the “intersection X” whereby the evidence of global warming is such that it reaches the point where’s it becomes economically and politically imperative to address.
“It’s the point of what is right for the world in the future and what your living electorate will allow you to do,” said Dr Alan Mendoza. “It’s when those issues intersect and if we haven't got to the intersection point yet we're heading there quite rapidly with extreme weather events that are showing people that something is not right. That's probably doing more to change opinions than anything else.”
It will test Mr Johnson’s diplomatic skills to secure NDCs which are an “absolutely top priority”, said Antony Froggatt, a climate and energy specialist from Chatham House think tank. “It's critical as people increasingly see the current implications of climate change. The UN call it ‘Code Red for humanity’ which is a soundbite but is still true because we can't allow global temperatures to carry on rising.”
The 2015 Paris agreement, which America withdrew from under Mr Trump but rejoined this year, committed to keeping global warming to below 2°C above pre-industrial levels, and preferably to 1.5°C.
But now it’s clear the proposed emissions cuts are not enough to meet the 2°C target.
Alok Sharma, the UK’s Cop26 president, has so far managed to persuade more than 110 countries to submit more ambitious NDCs. His boss – and perhaps British royalty as Prince Charles and the Duke and Duchess of Cambridge will be present – may now lean on the rest for concessions with much of the first few days of Cop26, starting on October 31, used to debate targets.
“Triumph can be measured in a broad communique that commits all participants to hitting certain targets by a clear date,” said Dr Mendoza, director of the Henry Jackson think tank. “What Boris has cleverly done, is present this as a leadership opportunity for the UK. At the end of this conference it will be, do we have a direction we’re mostly heading in together or do we not? If we do, that would be a successful conference.”
If NDCs are a priority, cash is a close second. The world’s richest countries need to pledge $100 billion a year to help developing countries build clean energy infrastructure and move away from fossil fuels.
“The $100bn is also crucial,” said Mr Froggatt. “It can significantly help with technology transfer. But it will be a question of faith and trust because for developing countries the issue of the lack of Covid-19 vaccines has undermined the feeling that we’re all in this together.”
The money will be a key point in winning over the poorer countries, agrees Dr Mendoza.
“It's very important that to show this isn't about a power game, it's not about stopping developing countries from reaching the economic heights they can achieve,” he said. “It is actually about helping them to change their economies to reflect what we need collectively."
Unlike some development aid projects this money would “directly benefit every single human being,” he said.
Another gain will be a global methane pledge, in which the EU and America want to persuade others to help slash the potent gas emissions by 30 per cent by 2030.
It will also be important to secure pledges from as many countries as possible to stop building coal power stations, at the very least by 2040.
This is where technology could really help, argues Mr Froggatt. “In a couple of years, I would anticipate that we could get tipping points in technologies to the extent that new renewables and new low carbon systems become cheaper than existing fossil fuel plants.”
That can make a huge difference, making it economically viable for countries to shut down coal in favour of solar or wind plants.
Expect to hear the slogan “coals, cars, cash and trees” from Mr Johnson, as well as his colourful and unique verbal skills that might prove effective in cajoling the waverers.
If the prime minister succeeds on securing significant NDCs and the $100 billion, that will mark the start of a long fight to ensure climate change does not become an irreversible fate for the grandchildren of today’s youth.
It’s difficult to contemplate failure at Cop26 as the consequences are so dire. But if all Mr Johnson achieves is multiple approaches with no common agreement, that will not bode well for the Earth’s future.