Just looking up Carlsen's Elo and it is still 2870.
I know his next goal is to reach 2900. Did the 3 wins in the world chess championship simply not give him any rating points, or does FIDE take a long time to update ratings?
With ELO (and most other chess rating systems I know of), it is difficult to substantially increase your rating when you play someone with a much lower rating. Also, whenever you draw against someone with a lower rating, that decreases your rating.
In the case of Carlsen's goal of 2900, where even the second highest rated player is 70 points below him, a draw is almost like a loss! And in a game where draws are very common at the top level, that makes Carles'n goal very ambitious. Still, if anyone can do it ...