Was the 12 years thing that we had 12 years before the impact of climate change was irreversible?
It was the lower bound of a perdition interval for the point of no return. Meaning we have as few as twelve years to end and reverse our carbon addiction before the negative impacts of climate change become inevitable. The prediction interval was something like 12-50 and the median was somewhere around 30 years. Some science writers and then politicians hyperbolized the prediction into “the world will end in 12 years.” This kind of thing is one reason why scientists should get more directly involved in policy processes.