Aldo Leopold’s “The Land Ethic,” published in 1949, is the seminal source for the subsequent development of environmental ethics as a sub-discipline of philosophy, beginning in the 1970s and growing exponentially ever since.  The Leopold land ethic is also the environmental ethic of choice among natural resource managers, conservation biologists, and other applied environmental sciences.  The land ethic, however, is scaled to local biotic communities and regional ecosystems: “A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community.  It is wrong when it tends otherwise,” wrote Leopold.  The over-riding environmental concern of the present century, however, is global climate change.  The land ethic cannot be coherently scaled up to a planetary scale—which is unfortunate, because of the enormous cache of the Leopold brand.  Fortunately, however, Leopold sketched an “earth ethic” based on an anticipation of the Gaia Hypothesis in 1923, urging non-anthropocentric respect for the whole Earth as a living being.  Leopold also expresses concern for “immediate posterity” and distant future human generations, thus also suggesting an anthropocentric Earth ethic.  Most people do care about their immediate posterity and concern for global human civilization can serve as a surrogate for distant human generations who may be beyond the reach our capacity for ethical regard.