The global reality of the climate crisis could hardly be more stark. A common theme is clear, from western Germany, where about 200 people perished in floods, to Henan province in central China, where at least 50 have died and about 400,000 have been evacuated after overwhelming downpours, to western Canada and the US, where a blistering set of heatwaves has provided the tinder for wildfires on a growing scale, through to the Middle East, where drought threatens communities from Algeria to Yemen, triggering unrest and regional disputes. On this planet there is no hiding place.

A hundred days now remain before the nations gather in Glasgow at the United Nations Cop26 climate conference on 31 October. More than 190 world leaders are expected. The UK government calls the summit the world’s last best chance. That is true. Yet words are cheaper than actions and sustained effort, especially when Boris Johnson is involved, and the last best chance is at serious risk of being lost. As things currently stand, the governments of the world, the UK included, are heading to Glasgow without having made the ambitious strategic decisions and collective sacrifices that might enable Cop26 to mark a genuine turning point that is needed in the battle to contain and reverse global heating.

This week, environment ministers from the G20 powers – representing more than 90% of the world’s economic production – have been meeting in Naples. This gathering ought to have provided a tremendous springboard towards Cop26. But the meeting has been short on concrete joint policy commitments of the kind that might create the necessary new political momentum. At the heart of the problem is the failure of the G20 to agree on actions and timetables to achieve global net zero greenhouse gas emissions by 2050. This is umbilically linked to the similar failure to set the more ambitious global goal of restricting global heating to an increase of 1.5C in the same period. Reports suggest that the ministers will recognise that 1.5C is preferable to 2C but not do enough about it.

This is unacceptable, but it is characteristic of a world struggling to recover economically from the pandemic. Governments’ recovery plans are increasingly falling short of what is needed to reach existing climate goals, never mind new ones. Globally, carbon emissions are again set to rise in 2023, not fall. The world is in danger of losing the path towards net zero. That failure comes down partly to money and partly to politics. Today, as in the past, responsibility should be widely shared. European countries, the UK included, often talk a better game than they play. On Thursday, Angela Merkel admitted as much about Germany’s record. “We can’t continue at the current pace but have to up the tempo,” she conceded.

There is little concrete evidence that Britain, as the Cop26 host nation, has done enough to make sure this happens. The task remains urgent. Without big developing countries such as Brazil and India on board, agreement is difficult, and these countries know they have bargaining power. The biggest carbon emitter remains China, where totals are still rising, and the US, whose emissions are falling but historically (and per capita) far exceed China’s. Together they are responsible for 40% of global emissions, so without them nothing decisive is achievable. The US climate change special envoy, John Kerry, is pledging extra money to support global climate initiatives but insists there will be no trade-off with China on human rights in order to secure a stronger climate deal. If an adequate agreement can still be reached, then Cop26 may yet be a success. But the clock is ticking and the stakes are getting ever higher.