The world is missing its lofty climate targets. Time for some realism – Global warming cannot be limited to 1.5°C

To accept that the world’s average temperature might rise by more than 1.5°C, declared the foreign minister of the Marshall Islands in 2015, would be to sign the “death warrant” of small, low-lying countries such as his. To widespread surprise, the grandees who met in Paris that year, at a climate conference like the one starting in Egypt next week, accepted his argument. They enshrined the goal of limiting global warming to about 1.5°C in the Paris agreement, which sought to co-ordinate national efforts to curb emissions of greenhouse gases.