Carlsen trades the central pawn, but  does so at a moment when the opponent somewhat spoiled his coordination.  Plus, he gains a long diagonal for his bishop.
1. e2e4  1... c7c5  2. g1f3  2... b8c6  3. f1b5  3... e7e6  4. e1g1  4... g8e7  5. f1e1  5... c6d4  6. f3d4  6... c5d4  7. c2c3  7... a7a6  8. b5f1  8... e7c6  9. b2b4 Fighting for the center from the flank. 9... f8e7  10. a2a4  10... e8g8  11. b1a3 