The threat to linguistic resources is now recognized as a worldwide crisis. According to Krauss (1992a), as many as half of the estimated 6,000 languages spoken on earth are "moribund"; that is, they are spoken only by adults who no longer teach them to the next generation. An additional 40 percent may soon be threatened because the number of children learning them is declining measurably. In other words, 90 percent of existing languages today are likely to die or become seriously embattled within the next century. That leaves only about 600 languages, 10 percent of the world's total, that remain relatively secure – for now. This assessment is confirmed, with and without such detailed estimates, by linguists reporting the decline of languages on a global scale, but especially in the Americas, Africa, Australia, and Southeast Asia (Robins & Uhlenbeck, 1991; Brenzinger, 1992; Schmidt, 1990).

Excerpt from conclusion:

Why Should We Care?

Why concern ourselves with the problem of endangered Native American languages, to the extent of investing the considerable time, effort, and resources that would be needed to save even a handful of them? Posing the question in this way may seem callous, considering the shameful history of cultural genocide practiced against indigenous peoples in this country. But, for many non-Indians, who tend to view linguistic diversity as a liability rather than an asset, the value of these languages is not self-evident. Knowledge about Native American issues in general is limited. Meanwhile assimilationist biases remain strong; hence the symbolic opposition these days to any kind of public expenditure aimed at preserving "ethnic" cultures (Crawford, 1992b). Until such attitudes are changed – by effectively answering the question, "Why should we care about preserving Native American languages?" – there will be limited progress in conservation and renewal.

Advocates have advanced a variety of answers. Let us consider them on their scientific merits and on their political appeal.

1. Linguists, who are increasingly vocal on this issue, have warned that the death of any natural language represents an incalculable loss to their science. "Suppose English were the only language available as a basis for the study of general human grammatical competence," writes Hale (1992, p. 35). While "we could learn a great deal ... we also know enough about linguistic diversity to know that we would miss an enormous amount." No doubt few who are acquainted with this problem would disagree: from a scientific standpoint, the destruction of data is always regrettable. Losing a language means losing a rare window on the human mind. But from the perspective of the public and policymakers, this argument smacks of professional self-interest; it is hardly a compelling justification for new spending in times of fiscal austerity.

2. Others have argued that the loss of linguistic diversity represents a loss of intellectual diversity. Each language is a unique tool for analyzing and synthesizing the world, incorporating the knowledge and values of a speech community. Linguistic "categories [including] number, gender, case, tense, mode, voice, 'aspect,' and a host of others ... are not so much discovered in experience as imposed upon it" (Sapir, 1931). Thus to lose such a tool is to "forget" a way of constructing reality, to blot out a perspective evolved over many generations. The less variety in language, the less variety in ideas. Again, a Darwinian analogy:

Evolutionary biologists recognize the great advantage held by species that maintain the greatest possible diversity. Disasters occur when only one strain of wheat or corn, a "monoculture" is planted everywhere. With no variation, there is no potential to meet changing conditions. In the development of new science concepts, a `monolanguage' holds the same dangers as a monoculture. Because languages partition reality differently, they offer different models of how the world works. There is absolutely no reason why the metaphors provided in English are superior to those of other languages. [Schrock, 1986.]

Theoretically this sounds plausible; yet such effects are impossible to quantify. Who can say whether a concept that evolved in one language would never have evolved in another? The extreme version of the Sapir-Whorf hypothesis – that perception and cognition are determined by the structure of whatever language one happens to speak – has been demolished by Chomskyan linguistics (see, e.g., Pinker, 1994). Its more flexible version, "linguistic relativity," is another matter. Few would dispute that culture, influenced by language, influences thought. Yet the impact remains too elusive, too speculative, to rally public concern about language loss.

3. Then there is the cultural pluralist approach: language loss is "part of the more general loss being suffered by the world, the loss of diversity in all things" (Hale, 1992, p. 3). While this argument is politically potent – with lots of cosmopolitan appeal – it is scientifically dubious. For at least one linguist working to save endangered languages, such "statements ... are appeals to our emotions, not to our reason" (Ladefoged, 1992, p. 810). Again the biological analogy breaks down. From the loss of natural species scientists are continually documenting ripple effects that harm our global ecosystem. No such evidence is available for the loss of linguistic species, which are not physically interdependent and which "evolve" in very different ways. No doubt it would be interesting to know more about extinct languages like Sumerian, Hittite, Etruscan, and even Anglo-Saxon. But how can we regard their disappearance as a global "catastrophe"? As for the threat to human diversity in general, "the world is remarkably resilient ...; different cultures are always dying while new ones arise" (Ladefoged, 1992, p. 810). Indeed, this resilience is the basis for linguistic diversity itself.

4. A final – and, in my view, the most effective – line of argument appeals to the nation's broader interest in social justice. We should care about preventing the extinction of languages because of the human costs to those most directly affected. "The destruction of a language is the destruction of a rooted identity" (Fishman, 1991, p. 4) for both groups and individuals. Along with the accompanying loss of culture, language loss can destroy a sense of self-worth, limiting human potential and complicating efforts to solve other problems, such as poverty, family breakdown, school failure, and substance abuse. After all, language death does not happen in privileged communities. It happens to the dispossessed and the disempowered, peoples who most need their cultural resources to survive.

In this context, indigenous language renewal takes on an added significance. It becomes something of value not merely to academic researchers, but to native speakers themselves. This is true even in extreme cases where a language seems beyond repair. As one linguist sums up a project to revive Adnyamathanha, an Australian Aboriginal tongue that had declined to about 20 native speakers:
It was not the success in reviving the language – although in some small ways [the program] did that. It was success in reviving something far deeper than the language itself – that sense of worth in being Adnyamathanha, and in having something unique and infinitely worth hanging onto. [D. Tunbridge, quoted in Schmidt, 1990, p. 106.]