There's definite evidence about the irreversibility like the release of trapped CO2 in ice that accumulated over tens of thousands of years. Riding of sea level

There's definite evidence about the irreversibility like the release of trapped CO2 in ice that accumulated over tens of thousands of years. Riding of sea levels will also take much more time to reverse than it took to happen. Technically it's all reversible as the world will see another ice age at some point but on a human scale it's not going to be.