The 1.5°C target may be out of reach, but climate action is still crucial

As a COP₂₆ During climate change negotiations in Glasgow, UK, in November 2021, a new slogan entered the vocabulary: “Stay at 1.5°C.” The phrase, on everyone’s lips from politicians to climate scientists, was aimed at maintaining the goals set as part of the Paris Agreement at the COP six years ago._{twenty one}In hindsight, this ambition was probably already fizzling out, destined to remain merely an empty slogan.

New Scientist The argument began in 2022, when expert opinion did not reflect their personal views or the data we were seeing. Scientists felt trapped and unable to speak out because limiting warming to 1.5°C above pre-industrial levels is still possible according to the laws of physics, but not realistic given the political, social and economic upheaval.

Since then, there has been a growing recognition that 1.5°C is unattainable, but there was no frank discussion of what that meant. Now, for the first time, researchers have explicitly rejected that, saying that 1.6°C is the best we can hope for, and that higher temperatures are more likely (see “Best-case scenario for climate change now is 1.6°C warming”).

Will policymakers finally realize that platitudes and slogans are not enough to combat climate change? Promises to “maintain” these targets are meaningless if we do not achieve the only means of preventing rising temperatures — reducing emissions of carbon dioxide and other global-warming greenhouse gases to net zero.

Unfortunately, the phrase “net zero” is losing its original meaning as a description of atmospheric physics, and instead being used by many to mean “environmental policy I don’t like.” This is dangerous, because extreme temperature changes have locked us in a vicious cycle of emissions that only a net-zero energy system can break (see “Efforts to combat extreme temperatures are making the situation worse”). If we are to have any hope of limiting warming, we need to learn from the failure of “stay 1.5°C” and not let “net zero” become meaningless.