There are many ways in which to answer this question. So, I will list three negative effects of globalization.
First, globalization divides the world into various sectors. For instance, most of the manufacturing is done in Asia. This creates a divided world. In many ways it is far better to have all industries in each country, so that there will be self-sufficiency. What happens if there is a natural disaster or an international conflict?
Second, with globalization, there is the need for transportation. With cheap oil, this might not be a problem, but with the rise of the price of oil, this becomes problematic. When the barrel of oil reached 150 dollars, this caused great problems.
Third, globalization often makes the rich richer and the poor poorer. For instance, manufacturing jobs in Asia pay little, conditions are far from ideal, all the while those in charge make a killing.