The target of 1.5C is unattainable.We need to stop hiding behind it

In his Cop27 speech last week, the UK's will he-go, the won't-he-go prime minister said that stopping the planet from dangerously overheating was still within our grasp, leaving many wondering just what planet he was on.

- Bill McGuire

According to Rishi Sunak, last year's Cop26 climate conference in Glasgow was about keeping alive the possibility of preventing the global average temperature rise since the Industrial Revolution from climbing above 1.5C. "Alive", as in connected to a drip, in a coma and suffering cardiac arrest every few hours.

One year on, the picture is even bleaker. Over the past 12 months, while the UK has held the Cop presidency, only 24 nations tightened plans (known as NDCs - nationally determined commitments) to cut their own emissions, while global carbon output continued to climb remorselessly. Now, surely, the goal of 1.5C must be on life support, just awaiting someone to flick the switch and wheel it off to the morgue.

I write this in my recent book, Hothouse Earth: An Inhabitant's Guide, and in the run-up to Cop27, the UN Environment Programme suggested the same when it announced that there was no longer any credible pathway to achieving the 1.5C target. But still, voices at Cop27 claimed that this is achievable - including that of the former British prime minister Boris Johnson. This is correct, in the same way, that someone tied to railway tracks in front of a speeding express train can, in theory, save themselves. Both are delusional.