JANUARY 2, 2017  MANCHESTER, ENGLAND—A new graffiti crew, clutching canisters of green spray paint, is roaming the streets of Levenshulme, but they are not tagging walls. Instead, the “graffiti grannies” – a group of activist pensioners – in this postindustrial suburb of Manchester, England, mark every hole in the sidewalk that could trip them up, challenging the city council to bring in the pavers. As players in a growing “age-friendly” movement, they are part of a revolution in the ways that cities are adapting to their rapidly aging populations.

Across the English Channel in the Netherlands, Harry TerBraak isn’t about to conform to any age stereotypes. He is 90, a resident of a small-town nursing home that also houses students seeking a rent-free room, and he doesn’t blink at being greeted as “dude” with a fist bump by his younger housemates. In an intergenerational experiment gaining traction across the West, old and young are learning from each other, re-creating a way of life that was once the natural order.

And in South Africa, Novusumzi Masala is simply focusing on the job in front of her as the caregiver for 13 grandchildren. In fact, her life consists of 13 of everything – 13 pairs of battered shoes scattered around her tiny two-bedroom house, 13 bowls stacked high above her sink. In Soweto, where the “youth bulge” is the real demographic challenge, grandparents like Ms. Masala, age 78, are rising to the occasion to cope with it.

The demographic shifts under way across the globe are unprecedented. Experts like Paul Irving, the chairman of the Center for the Future of Aging at the Milken Institute in California, says the trend lines resemble a hockey stick: Life spans were flat throughout human history until they shot straight up in the past century.

By 2020, for the first time, there will be more people on earth age 60 or older than under age 5. By midcentury, the World Health Organization (WHO) estimates that 2 billion people – 22 percent of the global population – will be 60 or older, up from 900 million today.

In almost every country in the world, average ages are rising fast, putting pressure on city councils, health-care systems, and national economies. Japan, where 33 percent of the population is already over 60, is the world’s oldest nation, while Europe and the United States are quickly catching up.

Yet it is in developing countries, from Chile to China to Iran, where the rates of aging are the fastest today, often adding a new dimension to existing social conflicts and poverty.

“Global aging, along with climate change, may be the great challenge of this century,” says Mr. Irving. “Unless policies and practices and norms and culture are changed, we have a tremendous problem, and if they are changed we have a remarkable opportunity.”

The key to the future, he says, is “purposeful aging” that empowers older people themselves as the agents of change. “Purposeful aging recognizes that people who age with purpose – this sense of meaning, direction, and desire to contribute – don’t just help others, they help themselves as well.”

Cities are on the front lines of these shifts, as people worldwide flee the countryside. In the world’s richest nations, older populations are expanding today more quickly in cities than anywhere else, with metropolises already home to 43.2 percent of those over 65.

That prompted the WHO to launch a network of “age-friendly” cities in 2010 with about a dozen affiliates; since then about 320 communities have signed up to rethink their urban designs and social environments.

“Around the world populations are aging, more people are living in cities, and these are accompanied by other demographic changes – increased women in the workforce, migration towards cities and hence children living away from their parents. All of these demographic changes have huge implications for cities and communities,” says Alana Officer, senior health adviser at the WHO.

Manchester, in the north of England, has in recent years been best known for its postindustrial makeover, which has drawn the young and hip. But at the same time it has been leading the way in rethinking the city for its senior citizens, and garnering worldwide attention – especially for relying on seniors themselves to effect change.

In Manchester, older people are volunteers and cultural champions. They oversee urban planning and sit on an advisory board that examines city policies through the eyes of senior citizens. “Having older adults in decisionmaking roles … means the community is able to draw on their skills and experience,” says Ms. Officer.

As their residents grow older, city governments are clearly going to have to undertake major long-term overhauls in housing and transport, for example. But a lot of what makes cities “age-friendly” today is micro. It can be as simple as rallying shopkeepers to set a chair outside a storefront, or spray-painting around a pothole.

The “graffiti grannies” have not stopped with spray paint. After shopkeepers denied an older man who uses a wheelchair access to the bathroom – he ended up wetting himself – the group launched the “Caught Short” campaign. Some of them in their 80s, they knocked on dozens of shop doors and asked who would say “no” next time. Then they published and handed out a leaflet, essentially a “where-to-go” guide, complete with information about wheelchair accessibility.

“These are tiny little things,” says Natalie Turner, senior program manager for Localities at the Center for Aging Better in London. “But it makes a big difference. It is the difference between having people [get] out, and having to stay home.”

Ms. Turner says one reason to adopt an “age-friendly” approach is that it respects older people’s rights, and the benefits are clear for seniors. John Johnson says that being part of the graffiti crew has kept loneliness at bay. “Some people carry on … [when they age], or go below. Others rise above. For me, getting older has brought me back to life,” he says.

But “age friendliness” also benefits society as a whole, when governments and residents start focusing on the upside. Some companies are looking at ways to employ older people longer, utilizing their knowledge as they keep economies productive. Others are focusing on older people as a market opportunity.

If older people do not find it easier to engage in their communities and stay active, they will end up more dependent, and more expensive, argues Turner. “We need to keep them employed, volunteering, caregiving,” she adds. “We need them.”

Developed Western countries are focusing mostly on aging cities. The government in China is more concerned by an aging countryside.

On a cold, foggy morning in Yanjing, a sleepy village on the outskirts of Shanghai, Fei Quying takes her place in front of 20 other widows and retirees for their morning exercise dance.

The sprightly 75-year-old smiles as she leads the others through choreographed arm swings and hip sways, set to “If You’re Happy and You Know It” sung in Chinese. The song plays over and over for 15 minutes from a nearby speaker.

It’s a lively scene for a community that not long ago seemed to be coming apart. Many of its young people had left to find work in the city, and homes had been abandoned.

“It was really sad,” says Ms. Fei, who has lived in the same house for 66 years. “Now this place brings old people together. It makes me much happier.”

“This place” is Happy Elder House, a 49-bed nursing home fashioned from 10 empty buildings and newly equipped with handrails and wheelchair ramps, a cafeteria, and a community center.

Retirement homes, standard in the West, are revolutionary in China, where the millenniums-old tradition of filial piety makes caring for one’s parents an essential duty.

But as more and more young people seek jobs in the city, far from their parents’ homes, ancient traditions are eroding, however hard the authorities try to bolster them. (A village in Sichuan province has taken to naming and shaming children neglectful of their parents by plastering their faces on billboards.)

“Society is changing,” says Peng Xizhe, a professor of population and development at Fudan University in Shanghai. “On the one hand, it’s important to maintain the … traditional arrangement for elderly support. But on the other hand, we have to find new ways of dealing with this.”

China has the most elderly people of any country in the world. More than 220 million people, or 16 percent of its population, are 60 or older. Demographers predict their numbers will rise to 490 million by 2050.

Who will look after them? Faraway children will never be able to provide their parents with daily care, points out Du Peng, director of the Center of Aging Studies at Renmin University of China in Beijing. He says society as a whole must work to fill the gaps.

“We will have more and more old people who need long-term care, especially in rural areas,” he says. “Local communities are the best places to provide the support they need.”

Back in Yanjing Village, Chen Guoqiang agrees. He has taken time off from his government job, a 40-minute drive away, to run errands and visit his father at the Happy Elder House.

“I have one child, a daughter. I don’t want her to have to take care of me,” Mr. Chen says. “I want to come here when I get older.”

You wouldn’t catch 85-year-old Rasmiya Mohammed, who lives in Baghdad, saying she did not want her daughter Hanaa to look after her.

War is never far from Hanaa Ghazi’s doorstep. The night before a recent visit, two bodies were found on a street near her Baghdad home. Days earlier, two children were kidnapped.

But Hanaa, a mother of three, has an even more immediate concern. She and her husband, Jafar, are caring for her bed-ridden mother, paying her high medical bills and making her comfortable.

“Even with all the difficulties, we will not let her down,” says Hanaa. “She is above everything. She is our top priority.”

And Ms. Mohammed, beaming from her bed in the living room with her 7-year-old grandson, Fadl, sitting happily by her side, knows how fortunate she is. “Thank God, everyone here loves me and takes care of me,” she says, wiping away a tear. “Many people, when they become very old, become humiliated or insulted by their family, who don’t care. I am lucky…. Even the small boys take care, and kiss me.”

The Quran requires Muslims to care wholeheartedly for their aging parents, and in Iraq and many other Mideast countries such support is a cultural norm as well as a religious obligation, with three generations often living under one roof.

But the stress of three decades of perennial crises has shredded Iraq’s social fabric. “Because of the wars, people have not thrown out their values, but there is a storm of dust covering all these values,” says Ena’am al-Badri, a sociologist and director of the Al-Selaikh Elderly Home, one of only two such state-run homes in Baghdad.

“The sanctions, the wars, and the violence don’t give us time to educate our sons in good ways,” adds Leila Abdul-Hossein Hamza, director of the private Mercy Home for the Elderly, a charitable organization with an adjacent orphanage run by Shiite cleric Ayatollah Hussein Sadr.

Kadriyah Saleh, 75, a resident of the Mercy Home dressed in the black shroud favored by devout Shiite Iraqis, has suffered the effects of such violent social dislocation. “I feel shame when I mention my son,” she says, recounting how he was an interpreter for US forces, and then left for America in 2005.

“I never heard from him again,” says Ms. Saleh. “He never said goodbye. He could have come.” Neither of her two daughters visits her, either.

She says she now feels cared for and doesn’t “feel like a stranger here ­– thank God for that.” And if there were no Mercy Home, which provides free care and a bed? Her answer is emphatic: “I would be on the street.”

Residential homes for older people are rare in Iraq, but they are attracting attention as symbolic green shoots of social responsibility, says Ms. Badri. Schools send their pupils to her state-run home to learn “how to care for people,” she adds. Even graduation parties have been held at the home “to support us. This is a big message for everyone.”

“There are signs of hope,” she adds. “There is a kind of uprising inside people. There are still many people trying to recover from their wounds, and people started thinking of how to heal society again. So people are rising up to face this.”

Still, most Iraqi families care for their parents themselves, despite the challenges. Hanaa spends half the salary she earns as a medical service worker to buy medicine for her mother. War prevented the family from sending her to a decent doctor years ago. International sanctions kept them from sending her abroad for treatment. Today, conflict right outside their door is again testing their ability to cope.

“There is big fear when we see all these things, bodies and explosions,” says Jafar. But his mother-in-law, he adds, is “a good omen for us. When I see her, it is like a blessing for the house and good things come to us.”

Novusumzi Masala is certainly a blessing to the houseful of kids she looks after in Soweto.

Africa’s challenge at the moment is less figuring out how to care for its older people, such as Ms. Masala, than thinking through what to do with its young people. And the elderly are playing a key role in shaping the next generation’s future.

“There’s often a perception that older people are vulnerable, frail, and irrelevant to what happens to young people, but we know that in reality the lives of older and younger people are closely linked – there is a skills and knowledge transfer there that needs to happen for society to function,” says Isabella Aboderin, a senior research scientist at the African Population and Health Research Center in Nairobi, Kenya.

Sub-Saharan Africa is, by global standards, a dramatically young region. Sixty percent of its population is under 25, and there are nearly 13 people on the continent between the ages of 20 and 64 for every one person over 65 – more than three times the European ratio.

In South Africa the bonds between young and old often revolve around orphans. There are nearly 4 million of them, half of whom lost their parents to AIDS. Continent-wide, UNICEF estimates that half of Africa’s 132 million orphans live with their grandparents.

For Joey Monane, who runs a Soweto-based youth organization called Ikusasa Lethu (“Tomorrow is ours”), that link is an essential one, and he has come to consider providing support to older caregivers in his community an essential part of his work to support the young people who are living with them.

Three mornings a week, after the kids finish breakfast and filter out of his center to head to school, the local grandmothers begin trickling in, ready for a day of crafts, support groups, and sports.

“We have a very good granny soccer team,” Mr. Monane says.

The center offers a welcome respite to grandmothers such as Masala, who is looking after 13 children between the ages of 2 and 17. “This isn’t how I pictured my old age,” she laughs, as a pair of toddlers scurry over her feet. “But I keep up. These are my family. I could never say no to them.”

Although Africa’s population remains tilted toward the young, Masala’s age group is also swelling as Africans, like people everywhere else in the world, live longer. That has not yet drawn much attention.

“Unlike what’s been happening in other regions where there’s a very explicit recognition that an aging population is a very serious development issue that requires planning and actions, this hasn’t yet been the case in sub-Saharan Africa,” says Ms. Aboderin.

Governments may not care, but the Masala kids do. On a recent morning, some of the older children presented their grandmother with a song they had written about their lives. It was a haunting rap ballad, and, unsurprisingly, she featured prominently.

“It’s a song about what we have been through and how, with the help of our grandmother, we have made something better from it,” says Ongezwa Masala, 15. “We’re singing about why we love her.”

•          •          •

At one time, growing up with one’s grandparents around was the norm in Europe and the US, too. Now moves are afoot to re-create the sort of atmosphere that has gotten lost as family units in the West have shrunk.

It’s not every day that someone living in a retirement home break-dances his way to a TV game-show prize by hopping upside-down on his right hand 75 times in less than two minutes.

But Sores Duman, who managed that feat recently, is not your everyday retirement home resident. He is a 27-year-old student, one of six living at the Humanitas nursing home in the provincial Dutch town of Deventer.

The setup is part of a movement catching on around the world, from Cleveland, Ohio, to Helsinki, Finland: intergenerational living. Studies have shown that social isolation and loneliness among the elderly are killers; contact with younger people is good for their health.

And contact with older people is good for the students, too.

Mr. Duman, his bushy black hair springing out from under a beanie, has lived in the nursing home for nine months and says his experience has reshaped his view of the world. “I used to look at elderly people and see their limits, what they couldn’t do,” he says. “Now I see their possibilities, what they can do. You have to see them as regular people, not as the elderly.”

The idea for an intergenerational nursing home came from Gea Sijpkes, the Humanitas director, who was searching for solutions amid government cuts to both elderly care and student aid. She offered rent-free rooms in her care home to local students in return for 30 hours a month of being a “good neighbor.”

“Maybe I can’t fix your bad knee, but I can make your living environment warm, funny, and surprising, a place you’d want to be,” she says.

The idea did not come without opposition from the board. “To them, students meant sex, drugs, and rock ’n’ roll,” Dr. Sijpkes recalls. “How could I think of letting them live amongst the vulnerable elderly?”

Yet living alongside the young, says Mr. TerBraak, the 90-year-old “dude,” makes him feel younger. “They do not treat us as if we were old, and that’s really important,” he says.

 

With people living longer, researchers are uncovering many upsides to cross-generation cooperation. “The wisdom and judgment and balance that come with age, combined with the energy and healthy risk-taking characteristics and creativity of youth, represents a really powerful opportunity for companies and countries,” says Irving, the expert on aging at the Milken Institute.

How society embraces people living longer – at home, in the office, in the mall, or at church – will revolutionize the way people experience getting older. “Longevity will change our religion, it will change our work, it will change our relationships,” he says. “Longevity will literally change everything.”