Costs and dangers
Housing is the biggest cost for most families. Growing financial and environmental pressures mean there are more bad choices about where we live. Consider the rising liklihood of drought, sea-level rise, flooding, or other natural disasters. Or a nuclear accident. Also the tax increases to fight these problems, plus the possible loss of our mortgage interest deduction, and other changes.
Ways to help ourselves
Although conservation is the low-hanging fruit for saving on energy, small energy-saving measures like CFL's don't do much. Affordability, and maybe even appreciation, is in home location and size. Choose a city with a good sustainability rating. Affordability now includes low transportation costs (#1 and #2), walkable neighborhoods, bikeable towns, and more. But make sure walkable/bikeable is defined properly for you.
Transforming an existing neighborhood is tough to do.
Living in towns with lots of college graduates protects against unemployment.
Passive solar, solar hot water, geothermal, or a deep energy retrofit can produce a safe home with low-running-costs.
Encouraging your state's promotion of renewable energy can help. Or moving to Canada for a climate change refuge, if you don't mind increased snow as the climate warms. Moving or retiring to towns where temperature rise is predicted to be slower may have advantages.
Ways to protect the community
Just walking around your neighborhood can strengthen ties with your neighbors that might soon be very useful.
Help us see ahead more clearly. Suggest other aspects of this topic we should explore.