How has globalization impacted the diversity of world cultures?

Well, globalization has positives and both negatives.

Positives in a more global world, you can meet people, exchange idea, science, math, inventions enriching the following cultures, however, there is a negative as well because others fear that globalization will ruin the diversity of cultures, and create a die out of certain languages. For example, some argue that the American McDonalds will ruin the cultural cuisine of France, Italy etc and drift into other aspects of local life from the health industry to daily interactions. This is also called "McDonaldization" or "Americanization" and is criticized by those who want to preserve local cultures.