Growing awareness of human impact on the environment in the 1960’s and 1970’s propelled an important cultural shift in how we relate to nature and how we should be managing the effects of technology, industry, and population growth.

Environmental ethics is a branch of philosophy that deals with the moral obligations that humans have towards the environment and all its non-human inhabitants. It involves exploring how humans should interact with the natural world, what responsibilities we have towards preserving and protecting it, and what intrinsic value nature holds. Environmental ethics considers questions about the rights of animals, the preservation of ecosystems, sustainable development, and the impacts of human actions on the environment.

As people grew more concerned about waning biodiversity, depleted ecosystems, and climate change, questions arose about the moral obligations we have to our environment. The field of environmental ethics soon came to fruition, and philosophers wrestled with questions such as: what environmental duties do we have as humans? Do we have obligations to protect the environment for its own sake or for our sake as humans? If we’re obligated to protect the environment for our own sake, is it for the benefit of humans at present or in future generations? As a collective, the development of environmental ethics represents an important moment of expansion in our sense of moral responsibility.

Anthropocentrism becomes one of the first debates in environmental ethics, revolving around the question of who or what we owe our moral obligations to. Anthropocentricism means “human-centeredness,” and it takes on specific meaning in environmental ethics with very powerful implications. It outlines an ethical philosophy in which the moral obligations we have to the environment are for the sake of our fellow humans. Under this school of thought, we have a duty to protect the environment because it will help us survive and thrive as a species. Anthropocentric environmental ethics has played an important role in the extension of our perceived scope of moral obligation, mainly to include future generations, but it has been heavily criticized for placing humans as the only beings with moral standing. Many philosophers have argued for an expansion of which beings humans owe ethical consideration, ranging from including all sentient beings to including other environmental entities like rivers and trees.

Philosophers Peter Singer and Tom Reagan are most famous for arguing that moral standing should be extended to animals on the grounds that they’re sentient beings, capable of experiencing pleasure and pain. They argue that consciousness creates an obligation for humans to give that being moral consideration, in a sense thinking of sentient beings as having certain rights that we must respect. These arguments have tremendous impact on environmental ethics because the extension of moral standing to include non-human animals implies much wider-ranging environmental obligations than anthropocentricism. It pushes us to weigh animal interests alongside human interests when making decisions about the environment and to give animal interests serious consideration. This extension of moral standing is what allows environmental decisions that are nothing but beneficial to humans to still be called into question if that benefit will come at the cost of animal welfare.

However, many philosophers still push back against this version of environmental ethics and call for greater extension of moral standing. Philosopher Aldo Leopold argued for the adoption of a “land ethic” long before environmental ethics arose as a field, and his ideas were picked up by people wanting to expand human moral obligations beyond being owed to sentient beings. Leopold famously wrote, “A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends to do otherwise,” and many thinkers in environmental ethics leveraged his arguments to expand our moral obligations to being owed to the environment as a whole—which would include non-sentient entities. This would extend our moral obligations to things like plant-life and bodies of water that are part of ecosystems, which the holistic environmental ethicist would argue have a right to flourish that should not be trumped by human ambition.

Environmental ethics has been pushing the extension of moral standing since its conception, and that movement has not gone uncontested. The boundaries of our moral obligations to our environment will undoubtedly remain a heavily debated point, and the placement of those boundaries will continue to influence the degree to which we, as a collective, weigh human and environmental interests either against each other or as one common interest.