1.5ºC is the lower bound for the estimated target. In any case, the 2ºC nominal target was mostly arbitrary. For those unaware, the problem with measuring glo

1.5ºC is the lower bound for the estimated target. In any case, the 2ºC nominal target was mostly arbitrary. For those unaware, the problem with measuring global temperatures is that we can measure variation (relative values) with great accuracy (e.g. 0.5ºC increase), but the error bars on the absolute measurement are way to big to make useful statements on what will happen at XºC.