It is true that some people think that human should have a global language in the future. Although there are some drawbacks of using a single language, I believe that there are far more benefits of social growth.
On the one hand, there are several reasons why speaking the same language could have negative impacts. Firstly, all countries would be loss of cultural and traditional values which is one of the biggest disadvantages on society. For example, the increasing popularity of English movies has significantly affected the lives of almost young people in Vietnam. They prefer to watch western films than locally produced films that might be the collapse of film industries in Vietnam due to the lack of audience. Secondly, using a single language causes the fall of tourism because there would be no reason to travel for meeting and learning about new cultures if all countries had the same language and similar cultures. This could damage many countries economically that are the most depend on income from tourism.
On the other hand, I believe that this trend could have some benefits on social development. One reason for this view is that a common language might facilitate the communication which contribute to boost in tourism. People could be easier travel around the world and go to places that speak different languages before. This is because, they would be complete understanding all cultures throughout the world. Another reason is that one language would help economic growth, especially multinational companies, business trade and global cooperation. For instance, companies like Samsung, Honda are easier trade between other companies. As a result, it leads to better performance of the employees and the company.
In conclusion, I think that a global language will have both advantages and disadvantages on social development.