Ecofiction (also "eco-fiction" or "eco fiction") is the branch of literature that encompasses nature-oriented (non-human) or environment-oriented (human impacts on nature) works of fiction. While this super genre's roots are seen in classic, pastoral, magical realism, animal metamorphoses, science fiction, and other genres, the term ecofiction did not become popular until the 1970s when various environmental movements created the platform for an explosion of environmental and nature literature, which also inspired ecocritism, the study of, among other ideas, humanity's connection with nature in literature. By this time, natural histories of ecology were modernizing, and literature followed. Environmentalists had claimed that the human relationship with the ecosystem often went unremarked in earlier literature.
According to Jim Dwyer, author of Where the Wild Books Are: A Field Guide to Ecofiction, "My criteria for determining whether a given work is ecofiction closely parallel Lawrence Buell's":
- The nonhuman environment is present not merely as a framing device but as a presence that begins to suggest that human history is implicated in natural history.
- The human interest is not understood to be the only legitimate interest.
- Human accountability to the environment is part of the text's ethical orientation.
- Some sense of the environment as a process rather than as a constant or a given is at least implicit in the text.' 
Definitions and explanations
"The terms 'environmental fiction,' 'green fiction,' and 'nature-oriented fiction,' might better be considered as categories of ecofiction....[Ecofiction] deals with environmental issues or the relation between humanity and the physical environment, that contrasts traditional and industrial cosmologies, or in which nature or the land has a prominent role…[It is] made up of many styles, primarily modernism, postmodernism, realism, and magical realism, and can be found in many genres, primarily mainstream, westerns, mystery, romance, and speculative fiction. Speculative fiction includes science fiction and fantasy, sometimes mixed with realism, as in the work of Ursula K. Le Guin." -Jim Dwyer [Ibid. Chapter 2.]
"Stories set in fictional landscapes that capture the essence of natural ecosystems....[They] can build around human relationships to these ecosystems or leave out humans altogether. The story itself, however, takes the reader into the natural world and brings it alive...Ideally the landscape and ecosystems--whether fantasy or real--should be as "realistic" as possible and plot constraints should accord with ecological principles." -Mike Vasey 
The distinction of true and false ecofiction was made by Diane Ackerman. "Often in fiction nature has loomed as a monstrous character, an adversary dishing out retribution for moral slippage, or as a nightmare region of chaos and horror where fanged beasts crouch ready to attack. But sometimes it beckons as a zone of magic, mysticism, inspiration, and holy conversion. "False ecofiction is based on the fear that something will go wrong, but true ecofiction is based on an integrative view of reality." -Gabriel Navarre 
Another perspective is that ecofiction is not divided between true and false, but into three categories: "Works that portray the environmental movement and/or environmental activism, works that depict a conflict over an environmental issue and express the author's beliefs, and works that feature environmental apocalypse." -Patricia D. Netzley 
"Ecofiction is an elastic term, capacious enough to accommodate a variety of fictional works that address the relationship between natural settings and the human communities that dwell within them. The term emerged soon after ecology took hold as a popular scientific paradigm and a broad cultural attitude in the 1960s and 1970s." -Jonathan Levin 
"Ecofiction forms a literature-based path towards an invigorated understanding of nature's place in human life and is part of a new phase in nature writing that seeks to include a modern consciousness in narratives of place. The Hopper believes that in order to refashion our lives to accommodate the knowledge we have of our environmental crisis, we have a lot of cultural heavy lifting to do. To reacquaint ourselves meaningfully with the natural world we have to turn our interpretive, inquisitive, and inspired faculties upon it." Dede Cummings, Green Writers Press
Ashland Creek Press often states that "ecofiction is fiction with a conscience." -John Yunker
Given that "Ecocriticism seems to be inherently interdisciplinary, cross-cultural, syncretic, holistic, and evolutionary in its nature," it would seem useful to apply these traits to the large field of literature that is ecofiction, especially given its history, reach, and continuity.
Interdisciplinary and holistic: Ecofiction can be seen as an umbrella for, or laterally relative to, many genres and subgenres and works well within the parameters of the main categories of speculative fiction, contemporary fiction, Anthropocene fiction, climate fiction, literary fiction, eco-futurist and solarpunk fictions, magical realism, ecological weird fiction, and more. Further, while ecofiction is "fiction with a conscience," per John Yunker, as shown above, it reveals integrity in the concern for our natural world as well as what can be found on numerous storytelling platforms: mystery, thriller, suspense, romance, dystopian, apocalyptic and post-apocalyptic, Arcadian, futuristic, crime, detective, and so on. Given the upstream and downstream effects of such issues as climate change, fracking, coal mining, animal justice, pollution, deforestation, and so on, this branch of fiction is not inclusive and has no demarcation other than the environmental and nature impacts by which it is defined and explained.
Cross-cultural and syncretic: Ecofiction is written by authors all over the world. Environmental issues, the desire to protect our natural ecological systems, and the praise of nature is an all-encompassing intention of many authors, which crosses all borders, languages, ethnicities, and belief systems. Many ecofiction novels incorporate LGBT and other egalitarian social issues that mirror sustainable, peaceful, and just environmental futures.
Evolutionary: Dwyer's field guide has hundreds of examples of ecofiction across time, from the roots and precursors---the earliest cave drawings, pastoral and classic, etc.--up through the 21st century. The continuity goes on. In May 2017, writing in The New York Times, Yale scholar Wai Chee Dimock reviewed Jeff VanderMeer's novel Borne and said, "This coming-of-age story signals that eco-fiction has come of age as well: wilder, more reckless and more breathtaking than previously thought, a wager and a promise that what emerges from the 21st century will be as good as any from the 20th, or the 19th."  Two months later, The Association for the Study of Literature and Environment's (ASLE) 17th biennial conference focused on ecofiction as one of its main streams. Ecofiction continues to be alive and relevant, evolving into contemporary study and a way of thinking about new literature.
Ecofiction, true to its evolutionary nature, encapsulates the most recent of our environmental crises: climate change. By the time Dwyer's big field study was published in 2010, already climate change had been engaging authors to write cautionary or disaster tales for a few decades. In his field guide, Dwyer cited such examples of climate change fiction as The Swarm and The Day After Tomorrow—also noting that "Ecofiction rarely fares well in escapist Hollywood." [Ibid. p. 92.] The first anthropogenic global warming (AGW) novel may have been Arthur Herzog's Heat, published in 1977, though plenty of novels up until then imagined or speculated climate change or events. While ecofiction has included AGW fiction since the 1970s, the past decade has also introduced newer specific genres to handle climate change, such as climate fiction, Anthroprocene fiction, and solarpunk. Thus, true to the evolutionary characteristic of ecofiction, from early pastoralism to modern science's understanding of global warming, hundreds of authors have taken up the issue of climate change in the least as a backdrop to their novels or, more heavily, as a moral, didactic cautionary tale centering around this foreboding, current, and very real environmental catastrophe. Eco-fiction.com's database lists hundreds of climate and other novels falling into the ecofiction genre.
The hyperobject, a term Timothy Morton used in Philosophy and Ecology after the End of the World, explains why it is so hard to write about climate change in fiction. Part of Morton's book's summary at Project MUSE states, "Moving fluidly between philosophy, science, literature, visual and conceptual art, and popular culture, the book argues that hyperobjects show that the end of the world has already occurred in the sense that concepts such as world, nature, and even environment are no longer a meaningful horizon against which human events take place. Instead of inhabiting a world, we find ourselves inside a number of hyperobjects, such as climate, nuclear weapons, evolution, or relativity. Such objects put unbearable strains on our normal ways of reasoning. Insisting that we have to reinvent how we think to even begin to comprehend the world we now live in, hyperobjects takes the first steps, outlining a genuinely postmodern ecological approach to thought and action."  For that reason, authors often take a fragment of a climate change to blow up in a story. An example of this is with Barbara Kingsolver's novel Flight Behavior, which is centered around a new winter habitat for monarch butterflies, after their traditional habitat is destroyed by flooding due to climate change.
While the term "ecofiction" is contemporary, as of the 1970s, its precursors are ancient and include many First People's fictionalizing nature in written form, including pictograms, petroglyphs, and creation myths. Classical literature, such as Ovid's Metamorphoses and Latin pastoral literature, continued this exaltation of nature as did Medieval European literature, such as Arthurian lore and Shakespeare's tales, followed by Romanticism, traditional pastoralism, and transcendentalism.
Dwyer notes that Kenneth Grahame's The Wind and The Willows, as well as many nonfiction authors, such as Ralph Waldo Emerson, Henry David Thoreau, John Burroughs, Margaret Fuller, and John Muir, had "strong influences on modern ecological thought, environmentalism, and ecofiction."
Up through the late 19th century, classics such as Herman Melville's Moby Dick, Mark Twain's The Adventures of Huckleberry Finn, H.G. Wells' The Island of Dr. Moreau, W.H. Hudson's A Crystal Age, and Sarah Orne Jewett's The White Heron and Other Stories and The Country of Pointed Firs, among many others, had eco-themes. In the 20th and 21st centuries, nature-related fiction evolved and continued, including eco-feminist fiction writers such as Charlotte Perkins Gilman and Mary Austin. Four "radical" authors also came on the scene: Jack London, D.H. Lawrence, B. Traven, and Upton Sinclair. Environmental science fiction also became popular from authors like Laurence Manning, George Orwell, William Golding, and Aldous Huxley. Regional environmentalists and authors, such as Zora Neale Hutson, William Faulkner, and John Steinbeck, also wrote about problems in their locales. Conservationists and environmentalists, such as Wallace Stegner and George R. Stewart, also contributed. J.R.R. Tolkien's mythology classics went down into history showing famous and iconic battles of industrialization vs. nature. Postwar ecofiction writers arrived too, such as science fiction authors who were cautionary about the environment: Clifford Simak, Jack Vance, Ray Bradbury, and Kurt Vonnegut, to name a few. Enter Peter Matthiessen and Edward Abbey, which Dwyer says are "arguably the most important and enduring new green voices to emerge in this period." And others, such as Jack Kerouac, Gary Snyder, and Michael McClure, represented "presentations of the nascent environmental consciousness of the Beat movement." [Ibid.]
This brings us up to the 1970s, when, as Dwyer points out, "ecofiction in all genres truly flourished...which might be considered the década de oro (golden age)," heralded by John Stadler's anthology Eco-fiction, containing science and mainstream ecofiction written between the 1920s and 1960s. [Ibid.]
Eco-fiction, the anthology, starts with this premise: "The earth is an eco-system. It possesses a collective memory. Everything that happens, no matter how insignificant it may seem, affects in some way at some time the existence of everything else within that system. Eco-fiction raises important questions about man's place in the system: Will man continue to ignore the warnings of the environment and destroy his source of life? Will he follow the herd into the slaughterhouse?" The anthology included the authors Ray Bradbury, John Steinbeck, Edgar Allan Poe, A.E. Coppard, James Agee, Robert M. Coates, Daphne du Maurier, Robley Wilson Jr., E.B. White, J.F. Powers, Kurt Vonnegut Jr., Sarah Orne Jewett, Frank Herbert, H.H. Munro, J.G. Ballard, Steven Scharder, Isaac Asmiov, and William Saroyan. Dwyer stated that the title of Stadler's Eco-fiction was his first knowledge of the term ecofiction. [Ibid.]
Jonathan Levin goes on to explain, "Two key events helped spark this new environmental awareness [leading to ecofiction]: the controversy surrounding proposed dams on the Colorado River that led ultimately to the construction of the Glen Canyon Dam (begun in the mid-1950s and completed about ten years later), and the 1962 publication of Silent Spring, Rachel Carson's exposé of the environmental impact of toxic pesticides like DDT. Both generated widespread media coverage, bringing complex and urgent environmental issues and the ecological vocabularies that helped explain them into the American lexicon." 
- The Association for Literature and the Environment (ASLE)
- The Association for Literature, Environment, and Culture in Canada (ALECC)
- European Association for the Study of Literature, Culture and the Environment (EASLCE)
- ResearchGate: Environmental Themes in Ecofiction: In the Center of the Nation and Animal Dreams
- Nature, Culture, and Literature
- AWP (2014) Panel: The Greening of Literature: Eco-Fiction and Poetry to Enlighten and Inspire
- Borne, Jeff VanderMeer
- Memory of Water, Emmi Itäranta
- Sherwood Nation, Benjamin Parzybok
- Nature's Confession, JL Morin
- The Water Knife, Paolo Bacigalupi
- Flight Behavior, Barbara Kingsolver
- Strange as the Weather Has Been, Ann Pancake
- The Jungle, Upton Sinclair
- The Monkey Wrench Gang, Edward Abbey
- Barkskins, Annie Proulx
- Float, JoeAnn Hart and My Last Continent, Midge Raymond
- Back to the Garden, Clara Hume
- Climate change in popular culture
- Climate fiction
- Ecological humanities
- Nature writing
- Speculative fiction
- Murphy, Patrick D. (2000). Further Afield in the Study of Nature-Oriented Literature. Charlottesville: University Press of Virginia. p. 1.
- Dwyer, Jim (2010). Where the Wild Books are: A Field Guide to Ecofiction. University of Nevada Press.
- Dwyer, Jim. "This Way to Sustainability Conference". Chico State. Chico State. Retrieved 1 October 2016.
- Vasey, Mike (February 20, 1996). Bioregional Studies - Correspondence with Jim Dwyer.
- Ackerman, Diane (2002). In Our Nature, Stories of Wilderness. Athens: University of Georgia Press. p. Preface.
- Navarre, Gabriel (1980). Earthworks: Ten Years on the Environmental Front. San Francisco: Friends of Earth. pp. 218–219.
- Netzley, Patricia (1991). Environmental Literature: An Encyclopedia of Works, Authors, and Themes. Santa Barbara, CA: ABC-Clio. p. 78.
- Levin, Jonathan (July 2011). The Cambridge History of the American Novel. Cambridge University Press. ISBN 9780511782046.
- Dwyer, Jim (2010). Where the Wild Books are: A Field Guide to Ecofiction. University of Nevada Press. p. 2.
- Dimock, Wai Chee (May 5, 2017). "There's No Escape From Contamination Above the Toxic Sea". The New York Times.
- "Rust/Resistance: Works of Recovery". ASLE. ASLE. Retrieved 24 June 2017.
- Mandel-Herzog, Leslie. "The Works of Arthur Herzog and a Talk with his Widow Leslie". Eco-fiction. Retrieved 21 July 2014.
- Bould, Mark (March 30, 2009). The Routledge Companion to Science Fiction. Routledge.
- Woodbury, Mary. "Eco-fiction Database". Eco-fiction.
- Morton, Timothy. "Hyperobjects: Philosophy and Ecology after the End of the World". Project Muse. University of Minnesota Press. Retrieved October 1, 2016.
- Dwyer, Jim (2010). Where the Wild Books are: A Field Guide to Ecofiction. University of Nevada Press. pp. Chapter 2.
- Stadler, John (August 3, 1978). Eco-fiction. Washington Square Press. ISBN 978-0671824785.
- Levin, Jonathan (July 2011). The Cambridge History of the American Novel. Cambridge University Press. ISBN 9780511782046.
- Nabhan, Gary Paul (2016). Ethnobiology for the Future: Linking Cultural and Ecological Diversity. University of Arizona Press. p. 278.
- Bunzi, Martin (2014). Uncertainty and the Philosophy of Climate Change. Routledge. p. 175.
- A Green Turn: Western Canadian Writers on Ecofiction (CanLit)
- Eco-fiction.com: Climate change and eco-themes in fiction
- EcoLit Books: Book Reviews and Writing Opportunities in New Environmental Writing
- 5 New Novels Make Fiction Out of Eco-Disaster
- Goodreads Listopia: Best Eco-fiction
- Library Booklists: Eco-fiction/Nature Fiction
- Ten Works of Fiction that Might Change the Way You Look at Nature
- Kenneth G. Bennett Books: The Rise of Eco-fiction
- LitHub: 5 Important Works of Eco-fiction You Need to Read
- North Castle's Children's Corner: What is Eco-fiction?
- Solarpunk Anarchists: Eco-fiction
- The Reverend's Guide to Ecofiction