Well the key things are
1. Introduction
2. at least 2 opinion with a few points about it for example:
There have been many who have stated that globalization is a dangerous matter due to many health risks that it may bring, for example that many endangered animals may not survive much longer as their food supply will drastically decrease,...
Second, the ozone who protects us from the UV rays become more and more damaged. The intensity will bring more and more skin cancer victims by the time .......
Yet on the other hand we have people who believe that this matter is simply a hoax due to...... and......
First of all....., secondly..... etc etc
3. Conclusion with your personal opinion.
If I remember right you gotta start with the thing that mostly has to do with your opinion.
I had to write an essay last year I think about globalization. Its not very hard