Delegates are arriving in Glasgow for a two-week conference that will test the willingness of world leaders to deliver on the promises they or their predecessors made in Paris six years ago.

As the host nation of COP26, the UK will be expected to demonstrate global leadership at an event that has been described as the “world’s last best chance to get runaway climate change under control.”

In 2015, nearly every country in the world signed the Paris Agreement, the first legally binding international treaty on climate change. Extensive in its scope and detailed in its content, it commits signatories to limiting global temperature rises to well below 2 degrees above pre-industrial levels, and to pursuing efforts to limit the temperature increase to 1.5 degrees above pre-industrial levels. It also encourages countries to take steps to deal with and mitigate the current impacts of climate change.

Signatories are also committed to aim to reach peak global Greenhouse Gas Emissions (GHG) as soon as possible and to take steps to rapidly reduce these and to achieve a balance between emission and removal.

The Paris Agreement requires all parties to commit to and publish the actions they will take to reduce GHG in the form of Nationally Determined Contributions (NDCs). The first NDCs were due to be published by 2020 and as of last month the UN Framework Convention on Climate Change had received 164 NDCs, including 86 new or updated NDCs from 113 countries.

Most significantly, the Agreement outlined how its ambitions would be financed, stating that “developed country Parties shall provide financial resources to assist developing country Parties with respect to both mitigation and adaptation”.

Developed countries were encouraged to significantly increase their climate finance ambitions/spending with the aim of mobilising $100 billion per year by 2020. The OECD announced that developed countries had delivered $79.6 billion of climate finance in 2019, up by 2% on 2018, but still short of the figure agreed in Paris.

Arguably, COP21 and the Paris Agreement were the “easy bit”, setting out the “what” in relation to the action needed to address the climate crisis, whereas COP26 is focused on “how” this will be achieved – something that could prove far more difficult to gain agreement on.

With the global economies still feeling the effects of Covid-19, what COP26 might realistically do is test the willingness of global leaders to achieve the Paris goals, none more so than the commitment to a collective goal of delivering $100 billion per year in climate finance.

The IPCC Sixth Assessment report outlined that the current ambitions of governments around the world are not enough to limit global warming to 1.5 degrees. However, the report added it is not too late to take radical action to undertake the necessary work to deliver quick and sustained reductions in GHG.

COP26 might not be the last chance to deliver the global action needed to tackle global warming, but if leaders decide to kick the can further down the road, limiting global average temperature rises to 1.5 degrees may permanently slip from the world’s grasp. The stakes for Glasgow are high.