'Keeping 1.5 Alive'?

It may just be my own confirmation bias (tendency to more readily accept things that support my own beliefs) in action. I have found myself nodding, however, in response to Bill McGuire's (Emeritus Professor at University College London) latest opinion piece (https://www.theguardian.com/commentisfree/2022/sep/12/global-heating-fighting-degree-target-2030). McGuire makes the point that the aspiration to limit global heating to 1.5 degrees Centigrade above pre-Industrial levels by 2030 (the 'Paris accord'), was 'arbitrary' (i.e. something of an educated guess). There was never any guarantee that 1.5 was a 'safe' increase. Encouraging participants at Glasgow's Cop26 to 'Keep 1.5 alive!', was essentially simple sloganeering. McGuire clearly thinks our chances of limiting global heating to 1.5 degrees, is now unachievable. He makes the point, however, that it may never be clear, when we have actually passed 1.5 degrees. Cyclical climatic events (like El Nino) might mean that global heating exceeds 1.5 in a single year, before temporarily (?) falling back. Will we only have 'Failed to keep 1.5 alive', when the global average is above that level for 5 or 6 years? McGuire notes that renewed media interest in 'Keeping 1.5 alive!', has been stimulated (see one of my earlier posts) by reports that the Earth's climate is rapidly approaching (or has even passed?) five 'tipping points'. Tipping points, changes, like the melting of Greenland's icecap, cannot be reversed. We already have seen, globally, a great increase in extreme weather events. McGuire points out that every 0.1 degree Centigrade rise is important and should be fought over. That might happen on a planet with rational leaders.