In 1997, Ecumenical Patriarch Bartholomew I of Constantinople coined the term “ecological sin” and since then his idea has come to influence a number of thinkers both within the Orthodox Church as well as others; the most prominent of which has been Pope Francis, who cites Bartholomew in his 2015 encyclical Laudato Si’ (sections 7-9) and who, in 2019, called for the inclusion of “ecological sin” within the catechism of the Roman Catholic Church. Yet, what precisely does it mean to commit sins against nature? What exactly does sin have to do with the natural environment? Isn’t sin about breaking God’s laws? And, since there are clearly no explicitly ‘environmental laws’ to be found within the scriptures or historical canons of Christianity, or even the other Abrahamic faiths for that matter, how can it be possible to transgress a law that does not seem to exist?
Well, this all depends on how one understands the ideas of “sin,” “transgression,” and “law.” The idea of “sin” is commonly thought of as entailing a transgression and, “transgression” is commonly thought of as violating a command. Yet, a “transgression” may also be thought of as exceeding a limit, or overstepping a boundary. Further, in religious contexts “laws” are often thought to connote divine “commands.” However, as we came to understand in the first part of this essay, St. Maximus Confessor had articulated an understanding of divinely authored “natural law” that was itself to be found not within scripture but within the “book of nature” itself. When trying to wrap our heads around the idea of “ecological sin,” rather than think of sinful acts solely in terms of disobeying scriptural commands, one way in which we might make sense of ecological sinfulness is for us to think about the notion of “transgression” in terms of the various planetary boundaries scientists have discovered by studying the natural world itself.
For instance, in addition to the biospheric tipping-points and the now well-known planetary temperature threshold of 1.5℃ to avoid disastrous climate change, climate scientists working at the Stockholm Resilience Centre have discovered a number of boundaries and thresholds of biospheric climate regulation and ecosystem vitality. Earth-systems science indicates that these planetary boundaries are: biosphere integrity (otherwise known as biodiversity loss), biogeochemical flows (otherwise known as phosphorus and nitrogen cycles), land-system change, freshwater levels, and atmospheric aerosol levels. Together these boundaries represent the optimal state of the global environment as it has existed within the Holocene, the geological epoch in which humanity originated and developed, and which is the only state of the Earth that humanity has ever known. Scientists warn that if we fail to maintain a Holocene-like state of biospheric stability we are likely to create conditions that will be far less favorable to human existence and which will drastically alter life on Earth as we know it, if not bring about its demise. Although such planetary boundaries may certainly be said to be the limits that any reasonable being ought not exceed if they wish to flourish and ensure the continuance of our species, it might be the case that these boundaries may actually be far more theologically significant than one might think on first glance. In more than a metaphorical manner, biospheric boundaries and ecosystem limitations may themselves be thought of as the ecological parameters of permissibility to human action that we ought not exceed or surpass if we are to achieve the good life and live in accordance with the divinely authored natural law.
When Ecumenical Patriarch Bartholomew I, Pope Francis, and Archbishop of Canterbury Justin Welby issued a joint statement for the protection of creation in September 2021 they said, “[w]e stand before a harsh justice: biodiversity loss, environmental degradation and climate change are the inevitable consequences of our actions, since we have greedily consumed more of the earth’s resources than the planet can endure” and correctly claimed that, “many of us behave in ways which demonstrate little concern for other people or the limits of the planet” (p. 3). The three pontiffs mention humanity’s failure to properly recognize the earth’s limits as part and parcel of our mistreatment of creation and I would argue that this failure to live within our planetary boundaries is one of our primary forms of ecological sin. Theologically, we may think of the Holocene as the aeon in which humans were bestowed with the gift of life and opportunity to flourish and that to act in ways that exceed the planetary boundaries is to transgress the natural limits set for us during the Holocene.
In the first portion of this essay, I had argued that theologians may garner ethical insight from the data garnered by environmental scientists and concluded with a call for theologians to enlist natural scientists as allies in their quest to better understand the natural law and for Christians, more generally, to become attentive to the lessons that may be learned from studies of the natural world as they respond to the ecological crises that we currently face. In this portion of the essay, I have argued that to knowingly transgress what scientists refer to as our “planetary boundaries,” is to directly disregard the wisdom to be found within natural creation itself, and as such may be said to be a form of disrespecting its divine author. Humanity must not allow itself to continue to act as a harbinger of death for natural creation as well as itself but rather we as humans must find ways in which our species, along with others in our common planetary home, can manage to flourish sustainably for now and unto the ages to come.
 Address of Ecumenical Patriarch Bartholomew at the Environmental Symposium, Saint Barbara Greek Orthodox Church, Santa Barbara, California. November 8, 1997
 Rockström, J., W. et. al. 2009. Planetary boundaries: exploring the safe operating space for humanity. Ecology and Society 14(2): 32.
 Steffen, Will et. al. 2015. Planetary Boundaries: Guiding Human Development on a Changing Planet. Science vol. 347 issue 6223.
 Rockström, J., W. et. al. 2009. Planetary boundaries: exploring the safe operating space for humanity. Ecology and Society 14(2): 32. The film Breaking Boundaries: The Science of Our Planet introduces audiences to these ideas in a very accessible way and a description may be found here: https://www.imdb.com/title/tt14539726/
Chris Durante, PhD, MA, MSc is an Associate Professor of Theology at Saint Peter’s University in Jersey City, N.J.; a Fellow of the UNESCO Chair in Bioethics & Human Rights in Rome, Italy; and a Fellow of the New Visions in Theological Anthropology initiative of the Science-Engaged Theology project of the School of Divinity at St. Andrews University in Scotland. Some of his work in science-engaged theology may be found at: https://www.theo-puzzles.ac.uk/?s=Durante
Public Orthodoxy seeks to promote conversation by providing a forum for diverse perspectives on contemporary issues related to Orthodox Christianity. The positions expressed in this essay are solely the author’s and do not necessarily represent the views of the editors or the Orthodox Christian Studies Center.