Here I talk about my latest research on the Brewer-Dobson circulation and the tropical climate sensitivity. The Brewer-Dobson circulation (BDC) is the global stratospheric circulation that brings air from the tropics to the extratropics. The BDC accelerates due to the warming produced by the CO2 radiative forcing. We find that accelerated BDC reduces the tropical equilibrium climate sensitivity. The tropical energy export increases as a consequence of the accelerated BDC. Therefore, the tropical effective radiative forcing weakens and, then, the surface warming ist smaller than without the BDC acceleration.