Fate of critical ocean currents is in our hands | Letters

George Monbiot (A catastrophic climate event is upon us. Here is why you’ve heard so little about it, 23 April) notes that, according to a recent paper, some scientists believe that the Atlantic meridional overturning circulation (Amoc) is more likely than not to “collapse”, implying a complete cessation. This is important because the Amoc brings substantial warmth to western Europe. In fact, the authors of the paper project an increased chance that the Amoc weakens by 50% by the end of the century under continued fossil-fuel emissions. Concerning as that is, they are projecting a slowdown, not a collapse. The outcome is not certain and with sustained efforts to reduce emissions there is still time to avoid the worst outcome. While the public needs to hear about the dangers, exaggerating the response of the Amoc from “weakening” to “collapse” gives the impression that there is no getting off the road to impending disaster. However, what the science is saying is that the fate of the Amoc is in the balance and actions we collectively take now to influence it. Andrew Watson Professor emeritus, Global Systems Institute, University of Exeter • Seven years ago, the Guardian changed its house style to favour “global heating” over “global warming” on the basis that that term more accurately reflected the environmental crises facing the world. “Climate change” became “climate emergency, crisis or breakdown”. George Monbiot’s excellent article justifies a further change – to “climate chaos”, or even “climate catastrophe”. Yes, there will still be heating in many parts of the world, but there is increasing scientific concern regarding the risk of an even more severe rearrangement of the climate system, with disastrous winter cooling occurring at the same time. Such changes have happened before in Earth’s history. They would not be as sudden as in the 2004 film The Day After Tomorrow, yet they could still be much too rapid for effective adaptation. Phil Williamson Honorary associate professor, School of Environmental Sciences, University of East Anglia • Have an opinion on anything you’ve read in the Guardian today? Please email us your letter and it will be considered for publication in our letters section.