One of the consequences of globalization is that even though there are more humans on the earth, the number of languages spoken is decreasing. As nomadic people and small tribes are assimilated into the wider population, and as powerful languages are increasingly taught in schools, it seems likely that in future all people will speak the same language. I do not believe this is a terrible thing, but it is not without its problems.
On the surface, it may seem as though the loss of languages is inherently negative. Our language is a part of our cultural identity, and without it people may feel a sense of loss. For example, some populations whose traditional language is dying out will lose their ancient stories and traditions, and feel that they are now no different from other groups of people. This problem is exacerbated by the fact that dominant cultures, whose languages are spreading throughout the world, maintain their cultural traditions.
However, although there are clearly some unfortunate side effects of this aspect of globalization, there are so many benefits that they outweigh the drawbacks. For one thing, the dominance of major languages like English ensures an increased level of literacy throughout populations where previously there were only oral languages or very limited written materials. While the loss of cultural artifacts is regrettable, the rise of literacy increases standards of living, and this is more important.
In conclusion, there are some undeniably negative consequences of a global language; however, the increase in literacy levels is an example of a benefit to humanity that vastly outweighs any imaginable drawback.