My understanding is that that's technically true, but not what they mean here. The idea behind 1.5C is that that's (supposedly, and probably given what we've o

My understanding is that that's technically true, but not what they mean here. The idea behind 1.5C is that that's (supposedly, and probably given what we've observed in 2022-2023) the point at which natural feedback loops kick in and climate change becomes non-linear. So for example, 1.3C is better than 1.4C is better than 1.5C. But if you cross 1.5C, you might get decreased albedo from glaciers melting, or increased methane emissions for permafrost. The result might be that you can't actually have a state with 1.8C in warming, because once you cross 1.5 you trigger natural feedback loops which bake in an extra 1C of warming. Total climate change jumps straight from 1.5C to 2.5C, because once you cross 1.5C it's not just us warming the planet anymore. It's still better to have 1.8C of emissions than 1.9C than 2.0, but the difference in actual temperatures might be 4.8C vs 4.9C vs 5.0, while if we could've just stayed under 1.5C we could've stayed under 1.5.