Today, several of the world's nearly 7,000 languages face a serious risk of extinction. "For example, Ainu, a language in Japan, is now seriously threatened, with only 10 native speakers left," said lead study author Tatsuya Amano at the University of Cambridge in England. The scientists found that 25 percent of the world's languages are threatened. After identifying where the endangered languages were, they looked for any environmental and social or economic factors those languages might have in common, such as rugged terrain or rapid population growth. "We found that at the global scale, language speaker declines are strongly linked to economic growth-that is, declines are particularly occurring in economically developed regions," Amano said. One important implication of this new study "is that languages in the tropics and Himalayan region are likely to be increasingly threatened in the near future, because these regions still have many local indigenous languages   with a small number of speakers, and at the same time are experiencing rapid economic growth," Amano said. Economic growth may endanger languages for a variety of reasons. For instance, speakers of endangered languages may view another more dominant language as offering economic opportunities, and thus forego their own languages. There are other important factors that might endanger languages, the researchers said. For instance, policies regarding how languages are used and taught in schools can be very different among countries and even within each country, and these factors may explain more detailed patterns in language endangerment. Amano suggested it could be possible to forecast future threats to linguistic diversity. "There exists detailed information on projected future changes in the environment, economies and climates," Amano said. "Using such information, together with the findings of this study and further analysis, we would like to understand what will happen to the world's languages, where it will happen and which languages will be threatened in particular." The writer shows us the reasons that languages are endangered by   _  .
offering some examples performing some experiments . telling some interesting stories making a list of important facts .