Boris Johnson doesn’t quite get his big moment in the Cornish sunshine

Delivering his closing press conference in the Carbis Bay hotel on Sunday, pale golden sand and azure sea visible behind him, Boris Johnson sought to play down the unseemly diplomatic spat that had marred his moment on the world stage.

“Actually, what happened at this summit was that there was a colossal amount of work on subjects that had absolutely nothing to do with Brexit,” he insisted.

Yet just hours earlier, his foreign secretary had been describing alleged comments by the French president about the status of Northern Ireland as “offensive”.

French sources flatly denied that Emmanuel Macron had been suggesting Northern Ireland was not part of the UK – they said he was merely pointing out it is not part of Great Britain (and, indeed, Northern Ireland has a special status under the protocol – which is of course why it exists).

Whatever the truth, Johnson’s bilateral meetings this weekend were repeatedly kiboshed by discussion of the ugly standoff over checks on products exported from Great Britain to Northern Ireland.

Rather than play down the row, the prime minister repeatedly leaned into it – saying he needed EU leaders to “get it into their heads,” that Northern Ireland is part of the UK, for example. The UK insists the EU is being too legalistic in how it interprets the protocol; but other G7 countries could have been excused for coming away with the impression that “Global Britain” cannot even get on with its nearest neighbours, and signs up to deals only to try to wriggle out of them later.

Away from sausage wars, there were new commitments from the G7 on boosting girls’ education, preventing future pandemics and safeguarding biodiversity. And there was a renewed sense that global cooperation is suddenly achievable again, in a way that was simply impossible in the Trump era, as illustrated by the minimum global tax deal struck by G7 finance ministers last week.

But on the two most pressing issues the world faces – the climate emergency and the pandemic – campaigners were bitterly disappointed by the scale of ambition on display.

The 1bn vaccine doses the G7 agreed to donate falls far short of the 11bn the World Health Organization’s Tedros Adhanom says are necessary to protect 70% of the world population. He would also like to see the donation deadline brought forward to next summer, from Johnson’s target of the end of 2022.

On climate, the G7 reiterated a decade-old promise to “mobilise” $100bn a year in financing, first made at the Copenhagen summit, which has already been about 80% reached. Leaders did commit to increasing their contributions to hit that total – but it was hardly the green Marshall Plan some reports had trailled.

Related: Johnson’s G7: after all the hype, what was actually achieved?

They said they would “develop a plan” for a clean, green financing mechanism intended to rival massive Chinese investment into developing countries – but details were scant. Like several announcements over the weekend, the headline appeared not to be backed up with policy detail.

At his press conference, Johnson bristled at the idea that the UK’s aid cuts may have undermined his moral authority to press other G7 countries to be more generous, whether on green finance or vaccines. He insisted no leader had brought up the issue of the cuts with him at the summit: and wrongly stated that the UK remained the second biggest donor in the G7 (it is the fifth).

But somehow, whether it was lack of diplomatic groundwork in advance, or the lack of trust created by the Brexit row, Johnson’s moment in the Cornish sunshine didn’t quite come off.

When it comes to Cop26 in Glasgow in November, when it is not just the wealthiest nations but the whole world the UK must cajole and persuade to back an ambitious climate deal, the challenges will be even greater, and the stakes very much higher.