Boris Johnson has made much of his ambitions for “Global Britain” post-Brexit, yet as his government faces the first fundamental test of its diplomatic prowess — at COP 26, the UN Climate Change Conference, which begins in Glasgow, Scotland, on Sunday — there are alarming signs that the event might be a bitter disappointment.

This might be the largest-ever international event staged in the UK, and to deliver on the ambition of the occasion the host of COP 26 would need to be a master of global diplomacy. It is therefore a tragedy that Johnson is in power in Westminster, leading a cabinet that does not include many of the most able members of the ruling Conservative Party.

To be fair to UK ministers, including COP 26 President Alok Sharma, the event in Glasgow presents a hugely tough set of negotiations; more so, in fact, than those in Paris in 2015, for at least two sets of reasons.

Firstly, the UK’s preparations have been significantly hampered by the pandemic and geopolitical tensions, with the latter meaning that some key leaders, including Chinese President Xi Jinping and his Russian counterpart Vladimir Putin, will not attend.

The second reason is that while the Paris meeting developed a new global climate framework, it is in Glasgow where the even harder work will begin of world leaders delivering on those ambitions by offering big cuts to their greenhouse-gas emissions through so-called Nationally Determined Contributions. So far, these NDCs do not get the world close to the ambition of limiting global warming to 1.5 degrees Celsius above pre-industrial temperatures.

And that is why UK ministers are frantically seeking movement in five key priority areas: the energy transition; the shift to zero-carbon transport; adaptation and resilience; nature and safeguarding of ecosystems; and unleashing green finance.

In what might be a “last-chance saloon” for international climate action, hopefully the UK government has not left it too late to reach a strong, ambitious deal in Glasgow.

Andrew Hammond

It will be enormously difficult to get substantive deals in all of these areas, however, and privately some key figures involved in the talks have admitted that a key headline goal of securing enough pledges on greenhouse gas emission cuts from major economies will most likely fall short of the halving of current levels needed this decade to reach the 1.5 C cap agreed in Paris.

Therefore it looks like the goal will instead become trying to keep the 1.5 C target alive, with the Glasgow conference potentially setting a pathway to avoiding the worst effects of climate change in the decades to come.

It remains possible, of course, that Johnson will do better than this and manage, with the support of allies, especially US President Joe Biden, to pull a rabbit out of the hat and deliver a deal that genuinely surprises. If that proves to be the case, he should be applauded for doing so.

However, the chances are the conference is just as likely to flop, which would be a disaster given that the Glasgow event is the most important COP since Paris six years ago. If so, there are good reasons why some of the blame for this would lie with the hosts.

Firstly, the preparations haven’t been given a political priority by Johnson and other ministers in the past few months, and it has not helped that he replaced his foreign minister last month. While Sharma has done extensive diplomatic legwork, having flown to more than 30 countries this year alone, Westminster has not thrown the full weight of the UK state behind the summit in the way that the French government did in 2014 and 2015 in the run-up to Paris, when it engaged in a wide-ranging global discussion to try to seek a consensus.

Moreover, whereas then-foreign minister Laurent Fabius, who in the 1980s was France’s youngest-ever prime minister, was the most effective COP president ever, Sharma, and indeed Johnson, lack clout on the international stage.

The UK government has poor relationships, post-Brexit, with much of Europe, its relationship with Biden is cool, and the actions of China, alongside other no-shows such as Brazil’s President Jair Bolsonaro, speak for themselves.

A second reason why the UK government would have some culpability is the mixed messages it is sending to the world through its policies. Sure, Johnson finally released last week his eagerly awaited net-zero strategy, which he hopes will go some way to bolstering the UK’s climate credentials before holding the international community to a higher set of long-term targets in Glasgow.

However, this comes at the same time that, in this week’s Budget, the government cut taxes on short-haul UK flights. This is by no means the only environmental faux pas Johnson has committed this year, with warnings, for example, that a planned new coal mine in Cumbria, in the north of England, is damaging his environmental reputation at the same time as he aspires to lead the world on climate change.

In what might be a “last-chance saloon” for international climate action, hopefully the UK government has not left it too late to reach a strong, ambitious deal in Glasgow. If it has, it will not just be letting UK public down, but the entire world.

• Andrew Hammond is an associate at the London School of Economics