Homelessness induced by mental health challenges. I know this isn't exactly what you were asking, but this is an area in which creating engineering solutions can go a long way. As suggested - think geographically local. Improvements in the way our society handles these issues, proven to work on a local scale, can be adapted and replicated globally.
Theory aside, I think our work as programmers has significantly changed the way society communicates and interacts. For better and worse. Would it not make sense that we continue this work, but more towards solving the issues we perceive, whether self-created or not?
I propose programmers spend more time talking to friends about challenges in their life that might be 'programmed' away, and less time on ads, tracking, manager checklist #321, or anything fundamentally centered around Business, because, let's be fair, on the whole, at least in 'the west', we as programmers have it incredibly good, so we can afford to be ideological.