When we say that morality does not exist between humans and animals, we mean that it does not intrinsically exist. A moral relationship always entails a second-person relationship of accountability.
Stewardship of the world goes beyond mere action and strikes at the heart of the Reformed Conservative. The way that God reveals Himself through His creation is why Christians ought to champion Godly Environmentalism.
Pantheistic and theistic approaches to environmentalism are universes apart. Francis Schaeffer understood the wisdom of an iconoclastic approach to correct the idolatrous approach of pantheism.