Either is correct, but mentioned is more idiomatic. If you were talking about a past conversation you had with a person, rather than reading an article, then it would be clear that the mentioning took place in the past: Last week I talked to Jim, and he mentioned how human activities are causing global warming.

Did they mention or mentioned?

You have to use an infinitive after did/does/do. This is why you wrote 'did mention' not 'did mentioned'.

Did I mention Meaning?

vb tr. 1 to refer to or speak about briefly or incidentally.