This paper investigates the consequences of environmental policy for w
elfare, consumption and production growth in a situation in which envi
ronmental quality is initially too low. The natural environment is inc
orporated in endogenous growth theory in a way that is consistent with
some simple notions from the laws of thermodynamics. Environmental po
licy affects growth, both in the long run and in the short run, by aff
ecting the productivity of investment and the savings behavior of cons
umers. The environment provides necessary inputs to economic productio
n and accumulation processes. Hence improvements in environmental qual
ity that follow environmental policy may boost the productivity of the
environment and growth.