This is Blue, Child of the Earth, an obscure (and I mean obscure) French cartoon from the 80's.
I remember a line from the title song as "Blue, the future lies (or rests) with you!"
You can watch the English-dubbed (but still written in French!) opening here. The line "Oh Blue, our future lies with you" happens at 0'40.
I think the antagonist of the show was named "the warlord"
You might be remembering the "Rock Lords".
and that Blue was the last man (or one of them).
Finding an actual summary for this is hard (especially on mobile), but this thread had someone remembering this series and mentioning
Basic plot was something in the future after the world was destroyed by something, failure of the environment I think.
So, the "last man" hypothesis seems to hold.
It was shown on our cable TV, but I cannot find it on the list of shows on TCC...
Someone requested it to be included in the list of shows aired by TCC on Wikipedia. Here's the edit request.
I was hoping someone could add the cartoon "Blue, Child of the Earth" to the list. I know and have seen a lot of people looking for this, and it would make it easier if it was on the TCC list of programs. It is French and the original title is "Bleu, l'enfant de la Terre".
It was eventually turned down because there was no source, and IMDb did not list it.
Not done: please provide reliable sources that support the change you want to be made. Thanks for the suggestion! However, IMDB doesn't say this program aired on TCC, and the second link is just an image. If we have a reliable source which says that Bleu aired on TCC, we can certainly add it! If you find one, feel free to re-enable the requested edit template, and someone will be by to put it in! Thanks!
Still, apparently the edit requestor remembered it being aired on TCC, which would match what you included in your question.
Found since it was mentioned in Identify an old animated film with bald blue people. I did not find an English dub right away, but this TvTropes post had it!