I think the novel you're referring to is 'Timescape', and it was written by Gregory Benford. From what I remember (and it's been 20 years at least since I read it), it's quite a bleak story.
Timescape and Red Mars are very different in very different in nature and size. Timescape is a self-contained end-of-the-world story, but set in a multiverse, so some of the characters do get out alive. Red Mars is the first part of a lengthy trilogy, which is ultimately optimistic about humanity itself, even though the story contains environment collapse, devastation, and war.
[Edit] To be clear, the overall story of which Red Mars is just the first part is much longer than Timescape.