I think as we move into a more ecologically unstable world, the earth-based religions will come to the fore. I sense that we feel that what we are doing is wrong and imbalanced, which may be reflected in our spirituality as a way of correcting it. If we go purely by numbers of those 'born into a religion' (a heinous concept), then Islam or Christianity will probably dominate. If that's the case, then gaining an ecological awareness is imperative within these faiths. The track record's not been too good so far...