Earlier quoted context omitted.
Get involved in local government. As someone else pointed out, most epic problems are social problems. Building a moon base was a technical challenge in like the fifties, and now it's an organizational problem of getting a hundred million people to agree to do it. Government is our primary mechanism for solving organizational problems; you can invent other ones, but why bother? Our government -- assuming you're in th…
Getting involved with local government may help to solve your local problems, but won't help with the epic ones. And from my own experience living and working in DC, getting involved with the federal government gives you only a very small chance of making a dent in whatever your pet issue is. I've worked with people who've lived here for 30+ years fighting for a single issue who've failed to make any meaningful progr…
In local government you can adjust zoning to encourage low-income housing and encourage multi-use residential/commercial zones. You can demilitarize local police forces and encourage a "protect and serve" attitude. You can set up needle exchange programs to reduce the spread of blood-borne diseases. You can accept refugees into your community.
There is also communication between different layers of government, both formal communication and informal networking -- a lot of state representatives and congressmen used to serve in local government. Getting involved in local government gives you another way to influence policy at a state and federal level.