We conduct a survey experiment testing the causal link between ethical justifications and acceptability towards two environmental policies: conservation area expansion and wildlife infrastructure. In a 2 x 3 experiment with American participants (n = 1604), we test two ethical justifications - anthropocentric justification (nature as instrumentally valuable) and a non-anthropocentric justification (nature as intrinsically valuable) compared to a control group. We find partial support that non-anthropocentric justification increases policy acceptability compared to no justification. Contrary to expectations, non-anthropocentric justification leads to higher policy acceptability than anthropocentric justification. These results are robust to individual differences in political orientation and environmental concern. Additionally, participants in the non-anthropocentric experimental condition respond that similar conservation policies generally are, and should be, passed to benefit wildlife and ecosystems compared to control group participants. Likewise, participants given the anthropocentric justification report that similar policies are, and should be, passed for humans and society compared to the control group.