  The present acceleration of the universe leads to the formation of a
cosmological future event horizon. We explore the effects of the event horizon
on cosmological backreaction due to inhomogeneities in the universe. Beginning
from the onset of the present accelerated era, we show that backreaction in
presence of the event horizon causes acceleration to slow down in the
subsequent evolution. Transition to deceleration occurs eventually, ensuring
avoidance of a big rip.
