SINCE the SNP came to power, clashes with the UK Government have become part of our political fabric.

They range from the explosive, such as court battles over Brexit, to the mundane, such as disputes over how much the Scotland Office spends on coffee and biscuits. But there was a reminder this week that tensions did simmer under the surface prior to the SNP’s 2007 victory. Government papers have revealed that the then-Scottish Executive wanted the UK government to pay the full £72million cost of policing the 2005 G8 Summit at Gleneagles. First Minister Jack McConnell threatened to publicly raise fears about the cost of security, according to the documents. The difference now is that SNP ministers wouldn’t just threaten, they would go straight to the nearest microphone.

The G8 event was an extraordinary moment when Scotland was at the centre of global attention. In Edinburgh, there was the power of the Make Poverty History march, the spectacle of the Live8 concert, and the ugliness of the city centre protests. One of my most memorable days as a cub reporter was being hemmed in with hundreds of protesters on Canning Street.

When he stood down the following year, then-council leader Donald Anderson said one of his highlights in the post was the way the city "rose to the challenge during the G8 summit". But spending disputes weren’t just between the UK and Scottish governments – Mr Anderson also had to spend time writing to Mr McConnell and Tony Blair about who was going to pick up the city’s bill.

Fifteen years on, and Scotland will once again be on the global stage this year.

This time it is Glasgow’s turn with the UN’s annual climate change summit, COP26, coming to the SEC in November. At Gleneagles there were only eight world leaders and 2,400 delegates at the summit. At COP26, around 200 world leaders and 30,000 delegates will attend. This is on a different scale altogether. It will be the largest gathering of world leaders in the UK since the opening ceremony for the 2012 Olympics, and it is less than a year away.

Predictably, there are early tensions between the UK and Scottish Governments.

SNP Justice Secretary Humza Yousaf has said Westminster must cover all of the estimated £100million policing bill. Given the UK is the host nation and the UK Government worked to secure the summit, it is perhaps not an unreasonable request. The Tory Government, for its part, has focused more on the politics of the event, with Boris Johnson telling an audience he doesn’t want to see Nicola Sturgeon "anywhere near it" and wants the area dressed in Union flags.

Given the Scottish Government has entered into a partnership with the Glasgow Science Centre on the opposite side of the river to host a series of events during COP26, he is unlikely to get his wish. Look out for aerial photos of Union flags on one side of the Clyde, Saltires on the other. But this summit is simply too important for flag-waving. In fact, this year is too important for flag-waving.

We start 2020 with huge swathes of Australia on fire. People have lost their lives, hundreds of homes have been destroyed, and thousands of people are fleeing towns. Climate change is here. The Prime Minister, Scott Morrison, is in trouble, berated by angry locals and under pressure to change his climate policies. The Australian government stands accused of failing to put in place the policies required to bring emissions down. Under the Paris Climate Agreement, the country set a target of making a 26-to-28 per cent reduction in emissions by 2030, but it is not on track. Mr Morrison also failed to attend a UN climate summit last year, and there will now be a great deal of attention on whether he travels to Glasgow – if he is still in office.

But as COP26 approaches, most of the attention will be on the host nation. Boris Johnson, who will sit in the summit chair, will come under intense pressure to show the UK is leading by example. When he comes to Glasgow to welcome the world, the global climate emergency should be his government’s focus – not getting one over on the Scottish Government by banning the First Minister or the Saltire. But so, too, should the SNP resist the temptation to make political capital out of the event, whether it is through grievance or one-upmanship. Some things are more important than trying to nudge those independence polling numbers closer to 50 per cent. If we have to have an intergovernmental row, can it at least be about how many trees are going to be planted across the UK, or how to work together to build a greener financial system?

It would be far better, however, if 2020 heralded a rare outbreak of political consensus. We have a unique political system in Scotland with two governments. Is it too much to ask that the administrations put their differences aside this year for the sake of the environment?

Because, frankly, this is far bigger than Scotland or the UK. There is hope that this time next year we will have a global green deal. The COP25 conference in Madrid disappointed many with its lack of progress in reducing greenhouse gas emissions. That makes COP26 even more important, creating an opportunity for a ‘Glasgow Agreement’ for the planet. It will require diplomacy to build on existing policies and a fresh round of more ambitious climate pledges. Mr Johnson has so far not shown great aptitude when it comes to diplomacy, but here is the greatest opportunity he will get.

So too must he show diplomacy when dealing with one of the big unknowns, which is America’s role in the summit. COP26 will take place just a few weeks after the US Presidential election. We won’t know until then whether delegates will have to navigate another four years of climate change denial with an emboldened Trump administration, or look forward to working with a more progressive incoming Democrat administration.

Back in 2005, at the G8 Summit in Gleneagles, the biggest media story involving the US President was when George W Bush collided with a police officer while riding his bike. COP26 will see a far bigger media debate about America’s future played out on the banks of the Clyde.

Here in the UK, the second decade of this century saw our political debate focus on whether to look more inwards. For the sake of the planet, the third decade must start by looking outwards.