Languages are tools for communication, but they are also the carries of culture, passing down ancient rites, traditions and wisdom each with their unique structures. Today, there are about 7,000 recognized languages worldwide. However, the world faces the threat of losing many of those languages and cultures forever.

According to a study from Australia, about half of all languages are endangered, and 1,500 could be extinct by the end of the century.

"Without intervention, language loss could triple within 40 years, with at least one language lost per month," the authors write. They advise creating curricula that support bilingual education and encourage both indigenous language mastery and the use of regionally dominant languages.

Fifty-one independent variables were analyzed, including education policy, socioeconomic indicators and environmental characteristics.

The study, led by the Australian National University (ANU), was published in the online journal Nature Ecology and Evolution.

The research also uncovered unexpected and surprising causes of language threat, said co-author Lindell Bromham. These include a well-developed road network, for example, he said.

"[W]e found that the more roads there are, connecting country to city, and villages to towns, the higher the risk of languages being endangered. It's as if roads are helping dominant languages 'steamroll' over other smaller languages," Bromham said.

Contact with other local languages, on the other hand, is not the problem: in fact, languages that come into contact with many other indigenous languages are less at risk.

The study also contains lessons for the preservation of endangered Indigenous Australian languages.

"Australia has the dubious distinction of having one of the highest rates of language loss worldwide," said co-author Felicity Meakins. Of the 250 languages once spoken by Indigenous people, she said, only 40 remain – and children learn only a dozen of them in the first place.