Underdiscussed: Language Death
Vae victīs: globalization poses the most severe existential threat to language diversity.
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According to the latest available data (as of this writing) from UNESCO, there are 2726 endangered or extinct languages, with over 7000 total languages discovered. That means 35 to 40% of the world's languages are threatened. With language death follows weakening of cultural ties and traditions, loss of folktales, oral history, and ancestral knowledge.