It’s both a challenge and a blessing: Most of us can safely assume we will live many decades, and that our health will be reasonably good even into older age. That’s the good news. The more complicated part is that most countries’ economic and social systems are organized around fewer old people than young, with the greater number of young people supporting the elderly. When we’re all living longer, the number of elderly starts creeping up. Pair that with a decline in the number of young people, as many choose to have just one or two kids (or none, in the case of people like myself) — and all of a sudden, the previous model is no longer applicable.

Plenty of Henny Pennies are pronouncing that the lower birthrate spells economic doom for us all, but it seems that the more logical, and less hyperbolic look at the situation is that it requires new organizational structures. After all, is encouraging people to have more kids than they want a smart public policy move? And is more people for the sake of propping up old systems really a long-term sustainable answer? We can’t keep making each generation bigger forever on a planet with limited resources, even if we use those resources as intelligently as we can.

The numbers are sobering: By 2020, for the first time in human history, there will be more people on Earth older than 60 than under the age of 5. In Japan, the “oldest” nation in the world, already more than one-third of the population is over 60. The United States and a number of countries in Europe aren’t too far behind.

So we need some new ideas about how to live in the future in innovative ways that may be different than how older people live now or have in the past. Here are just a few of the creative ways older people may be living in the future.

Intergenerational housing and programs

Millions of people saw this beautiful video last year that showed elderly people playing with, reading to, and generally having fun with very young children at a Seattle daycare center that was run inside a nursing home. The two groups moved at about the same speed — a bit more slowly. And both seemed to appreciate being able to go at their own pace. What makes more sense than to include older people in the care and education of the very young? This frees up parents and relieves at least some of the burden on them — and after all, in most societies up until the present, grandparents helping to care for and educate young kids was the norm.

Or how about 20-somethings and the elderly living together? Both groups need affordable housing, and the young people can both learn skills from the older cohort, as well as assist them with simple chores that might be tough for elderly hands or backs to handle. It works surprisingly well in experimental situations in Chicago, the Netherlands, and Germany. At the Pat Crowley House in Chicago, 19-year-old Carla Beig told the Chicago Tribune. “You give a lot, but you also get a lot back. We have more in common than you think.”

Other communities are being designed to keep all ages of people together, instead of segregating older people off by themselves, so that they maintain being part of a community, whether their own younger family members are around or not.

Age-friendly cities

As Lloyd Alter has written on MNN, some seniors want to continue living in suburban cul-de-sacs where services are scarce, and isolation is all too common; yet many others are choosing to live in cities, where quality of life is high, great medical care is nearby, transportation is organized around walking, and things to do are abundant. After all, just because people are of a certain age doesn’t mean they have the same interests.

Many cities are slowly but surely reorienting themselves around senior populations. Some of them are part of the World Health Organization’s “age friendly cities” network. This means that a city includes older people on planning committees, as well as ensuring public transit is friendly to that group. In an area of Delhi, India, that means putting the elderly in direct contact with police (they serve as eyes and ears for local law enforcement), and in Oslo that means organizing walkathons that include those who use walkers and canes, or are wheelchair-bound.

Portland, Oregon, offers another example of how cities can be friendlier for older people: With the city’s neighborhoods originally organized around streetcar lines with neighborhoods at their termini, these towns-within-the-city boast senior-friendly features. “Within walking distance is a library, several coffee shops and restaurants,” Barbara Bernstein, executive director of the nonprofit Elders in Action told Forbes.

Keep seniors working and empowered

Keeping seniors busy and productive keeps them sharp: “We need to keep them employed, volunteering, caregiving. We need them,” Natalie Turner, senior program manager for Localities at the Center for Aging Better in London told The Christian Science Monitor.

In fact, an investigation in Singapore has looked into the idea that reverse aging can occur when previously under-stimulated elderly are given a sense of mission and empowerment.

As the video above shows, their mood and cognitive performance improved when they were stimulated and involved in their communities. The way seniors are treated today in some nursing homes, where they are expected to do little for themselves, may be unhealthy for them.

By working, planners are not suggesting seniors just push their retirement later (though some prefer to keep going if they love their work), but that they contribute in ways that have proven to extend lifespan, health in older age, and overall happiness. Keeping physically active and mentally busy throughout the 70s and 80s is not only possible, but preferable for many. From old-age communities where basic farming chores are on the daily “to do” list (resulting in fresh, delicious veggies and a sense of pride), to others where the focus is on cooking meals together, there are myriad ways to both involve older people in a community, and keep them active in ways that benefit everyone — most of all the seniors themselves.

Homefarm, a conceptual vertical farm/retirement community in SingaporeArchitectural studio SPARK is working on a conceptual retirement community that takes a novel approach: by encouraging seniors to work at the on-site urban farm. (Renderings: SPARK)