1. It's an article for the school paper.
2. It's a "special interest" piece written as part of a temporary column (meaning he is a guest writer, not a staff journalist).
3. It's an opinion piece, written in a somewhat humoristic style, rather than factual "unbiased" journalism.
http://en.wikipedia.org/wiki/Editorial
#3 alone makes it editorial. #1 and #2 together should have given a clue, as well.