From Birger Johansson, Umeå, Sweden
The UN Environment Programme has defined the huge scale of the task of limiting temperature rise to 1.5°C, reports Adam Vaughan (30 November 2019, p 7). But things could be worse.
In recent research, Rishav Goyal and his colleagues showed that the world dodged a bullet when the , phasing out chlorofluorocarbons (CFCs) (Environmental Research Letters, ). CFCs are very potent greenhouse gases, as well as ozone destroyers. Their study shows that climate change would be catastrophic rather than merely panic-inducing if they had continued to be produced.
