That 3°C by 2050 figure comes from one particular group of German scientists. It is not the broad consensus, which is that we'll reach 3°C by around 2100.

Either scenario is obviously terrible and we need to begin to deal with it firmly and immediately. But I thought it was worth making clear that "the scientists" here only a small set, not the community as a whole, who have an only-slightly-less dire scenario.