If these local ties (of languages) dissolve, our entire species has less connection to Earth, less ability to sustainably manage our resources, and less knowledge of how to care for our planet. From the outback deserts to the Pacific Ocean's coral reefs, from the Andean glaciers to the Himalayan foothills, we find major stress points of human impact on ecosystems we do not fully understand. Endangered languages hold the key to a fuller understanding of these ecosystems and humankind’s place in them (Harrison 2010: 16).
The communication function is usually the first feature thought of language. However, the cognitive function of language may be even more fundamental, separating and ordering the chaotic environment that surrounds people. Miyaoka (1996, 2002, 2015) describes the human environment as a group-based "environmental world", incorporating the following three types of environments: the natural, the social, and the supernatural. Human groups thus place themselves in a cohesive environment that combines the social environment, of which they themselves are a part, the supernatural world (that of ghosts, spirits, and myths) that we have built ourselves, and the natural environment, in which we are incorporated as animals (Miyaoka 2002: 23). Miyaoka characterizes human language as transforming the chaotic continuous world, or chaos, into an ordered discontinuous world, or cosmos. Human beings use language to create culture and use culture as a cushion to allow them to confront their environment. Miyaoka (2002) describes the deep relationship between language and the environment in the following terms.
Humans communicate with others using a language that they rely heavily on to recognize the "environment" that surrounds them, and plan adaptation strategies to the "environment." From that point of view, we must say that "language is culture" rather than "language is the core of culture." If we understand "culture" in this way, the environment in which the group lives is not just a "cultural ecosystem," but it could even be said that it is a "linguistic ecosystem" in which language is widely permeated (Miyaoka 2002: 26).
This concept of the linguistic ecosystem identifies three functions of language: cognition, transmission, and direct functions. Cognition is a function that supports the entire ecosystem, and it is the most fundamental function of language, separating and categorizing all things in the world. Humans selectively incorporate the objective world into their own environment using language, organizing and classifying it into a finely hierarchical and multilayered structure using the type of cognition unique to the group, then naming and fixing things in place (Miyaoka 2015). Transmission is generally the best understood function. Using this function, people adapt to their environment through communication and collaboration with those living in the same society. Finally, the direct function involves speaking or, rather, using the language itself. For example, immigrants, families, lovers, and peers share and use specific words to confirm and strengthen their identities. Other examples here include soothing greetings, ritual clichés, rabble-rousing speeches, and the use of buzzwords.
Where in language do we see the environment understood by language’s cognitive function? Edward Sapir, a leader in American structural linguistics, writes the following.
It is the vocabulary of a language that most clearly reflects the physical and social environment of its speakers. The complete vocabulary of a language may indeed be looked upon as a complex inventory of all the ideas, interests, and occupations that take up the attention of the community, and were such a complete thesaurus of the language of a given tribe at our disposal, we might to a large extent infer the character of the physical environment and the characteristics of the culture of the people making use of it (Sapir 2012: 228).
For this reason, we can find a number of words in our native vocabulary that cannot be translated into languages used in different cultures and environments.
In an ethno-linguistic study of the Hanunoo language conducted in Mindoro, Philippines, Conklin (1955) found that Hanunoo identifies 1625 species of plants. The Hanunoo people use 150 part names to classify plants, and these plants and their parts are used for various purposes, including food, medicine, and tools. Hanunoo is a treasure trove of knowledge about plants.
Another example comes from the work of Harrison (2007) on Tofa, an endangered language in South Central Siberia, which has a finely categorized vocabulary regarding reindeer, on which the Tofa greatly depend. Their one word chary carries the high-density information that its object is a 5-year-old male castrated rideable reindeer. This vocabulary carries valuable wisdom in close relation with their daily work, allowing them to communicate and understand the age, gender, ability to be ridden, fertility, proficiency, and so on of their reindeer, quickly and accurately.
A language is nurtured and cultivated in the context of the human life in the environment surrounding the group that speaks it. From this point of view, when the relationship between a language and the environment in which it is developed collapses or is damaged, the language, too, begins to decline and, in the worst case, dies. This can be from various causes, including military subjugation by other groups, the migration of native speakers, the modernization or Westernization of traditional societies, and environmental changes due to climate change.