Letter: The problems with talk of a 1.5°C climate 'goal'

From Michael Grubb, professor of energy and climate change, University College London, UK

Anyone can look up the Paris Agreement (PA) text on curbing global warming to see that calling 1.5°C a “goal” is wrong. This matters for several reasons (18 January, p 8).

First, many lower-income countries regarded 1.5°C as fundamentally inequitable, given the implication that high-income countries had used up most of the carbon budget for this and were implicitly now trying to “cut the ladder” on the use of fossil fuels for basic industrialisation. Some thus regard the popular “1.5°C limit” narrative as a breach of trust on what was actually agreed.

Second, the limit narrative diverts from the reality that – as your leader said – there isn’t a warming cliff edge, but rather that every tenth of a degree matters. The actual aim of the PA to remain “well below 2°C”, while “pursuing efforts” for 1.5°C, reflects the balance of concerns.

A durable legal agreement couldn’t rest on a single threshold that many considered undeliverable. Focus on 1.5°C as “the limit” risks undermining the PA’s credibility.