  We investigate the future evolution of the universe using the Buchert
framework for averaged backreaction in the context of a two-domain partition of
the universe. We show that this approach allows for the possibility of the
global acceleration vanishing at a finite future time, provided that none of
the subdomains accelerate individually. The model at large scales is
analogously described in terms of a homogeneous scalar field emerging with a
potential that is fixed and free from phenomenological parametrization. The
dynamics of this scalar field is explored in the analogous FLRW cosmology.
  We use observational data from Type Ia Supernovae, Baryon Acoustic
Oscillations, and Cosmic Microwave Background to constrain the parameters of
the model for a viable cosmology, providing the corresponding likelihood
contours.
