Cop26 will fail unless rich nations keep their promises to the vulnerable – we cannot afford to be divided

The willingness of the poorest states and developing countries to enter into an agreement depends on the richest nations providing at least the $100bn a year they have pledged

Justice for all? A recent climate protest in Berlin (EPA)

What President John F Kennedy said in the 1960s, about the nuclear threat, is even more relevant to the environmental threat in the 2020s: every man and woman lives under a sword of Damocles hanging by the slenderest of threads.

And after a summer of devastating storms, floods, droughts and fires, Cop26 – the UN climate summit to be held in Glasgow in November – is the world’s best, immediate hope of avoiding a climate catastrophe.

This week Boris Johnson has highlighted commitments on “coal, cars and trees” but, as he knows, Cop26 can only succeed if we make more comprehensive progress in key areas. All countries must ratchet up their near-term carbon reduction targets for 2025 and 2030 and each sponsor a green new deal that offers millions of good jobs in the sustainable technologies of the future. All companies must agree to disclose their carbon footprint and, by setting their trajectories to achieve net carbon zero, start the switch to impact based accounting.

But the very success of Cop26 – and the willingness of vulnerable states and developing countries to enter into an agreement – depends on the world’s richest countries honouring an as yet unrealised, 12-year-old promise to transfer upwards of $100bn (£73bn) per year to coastal states and low-income countries to help them to adapt and be resilient to climate change.

I led the UK government that, in 2009, initiated the $100bn proposal that brought the US and Europe on board. We knew that, as Arctic and Antarctic ice disappears, floods and fires increase, and threats to biodiversity multiply, the poorest people in the poorest countries will be hit hardest. Announced at the Copenhagen summit and re-announced in 2015 in the Paris Climate Agreement as a key element in holding global warming to 1.5C. above pre-industrial levels, the $100bn was money to be transferred from the global north to the global south.

As the language used in the climate change agreements makes clear, states have “common but differentiated responsibilities and respective capabilities” to pay, taking account of wealth, population and carbon emissions to determine how much of the $100bn each country should contribute.

But instead of countries agreeing an equitable sharing of the burden, we have treated the business of raising $100bn like organising a whip-round at a charity fundraiser. In no year since 2009 has the fund ever yielded more than $40bn of the promised $100bn. It is only when multilateral bank disbursements and private funding – mainly in loans for renewable energy projects – are added that the annual sum finally reached $80bn in 2019, still well below what was promised.

Only Germany, Norway and Sweden, of the 23 developed countries responsible for providing international climate finance, have been paying their fair share. France and Japan came close in 2018, but even now the contributions from Australia, Canada, Greece, New Zealand, Portugal and the US have been meagre. Up to now they have transferred less than 20 per cent of their proportionate share, with the US – for example – having provided $1.9bn in 2019.

While the administration of President Joe Biden has now pledged $11bn a year pending Congressional approval, and the UK has promised to double its contribution to the climate pledge, the Overseas Development Institute's detailed study shows that this still falls far short of what they should be contributing.

Even after Canada has offered an additional $2.1bn, and Germany $2.3bn (by 2025) this takes us only to $90bn ahead of the Glasgow summit. An analysis from Oxfam says that based on current pledges the total will not reach beyond $95bn in any year before 2025. What’s more, with the majority of funds going towards dealing with short-term mitigation and 70 per cent of that being loans, far too little is currently financing long-term adaptation such as coastal storm defences and drought resistant crops.

And so, environmental pressure groups are now calling not just for a definitive commitment to $500bn in the five years – between now and 2025 – but for much larger investment as envisaged in President Biden's Build Back Better World initiative for green infrastructure investment.

Until developed countries outline a credible path to making good their promise, vulnerable countries will not trust any pledges made on future emissions reductions and they could decide to bring Cop26 down. So it is imperative that in the days between now and the start of Cop26 the $100bn a year is finally achieved. The money could come from using reallocated special drawing rights, the international money that every country receives, and by the expansion of World Bank funding.

But I want us to do even better than $100bn a year – and under proposals that have been floated for guarantee-based funding, each dollar we offer could go further. For every $5bn of guarantees and $1bn of grants from the wealthier countries, $25bn of extra finance can be raised for adaptation.

And if we also agreed to cover interest payments and eventually pay down the borrowing incurred, then we could rebuild the fractured trust between global north and south.

Uniting all parts of the world around a shared mission is indeed, a pre-condition of further progress. Prosperity has to be shared to be sustained and Cop26 must become Co-op26. This much needed, but still far too elusive, cooperation will only happen if we start to honour our responsibilities to each other.

Gordon Brown, UK prime minister from 2007 to 2010, is the author of 'Seven Ways to Change the World'