Cities around the world are growing faster than you can say megalopolis. More than half the world lives in cities, and by 2050, it will be two-thirds. In China alone, 300 million people will move to the city within the next 15 years, and to serve them, China must build the equivalent of the entire built infrastructure of the United States by 2028.

At the same time, 250 million new urban dwellers are expected in India and 380 million in Africa. Even though cities will soon account for 90 percent of population growth, 80 percent of global CO2, and 75 percent of energy consumption, more and more, it’s where people want to live.

Why? Because it’s where 80 percent of the wealth is created, and it’s where people find opportunities, especially women in the developing world. But beyond basic needs from housing to jobs, how do we enjoy the benefits of the city—like cafes, art galleries, restaurants, cultural facilities—without the traffic, crowding, crime, pollution, and disease?

Dozens of MIT faculty are now working to figure it out, and there is no easy fix. The problems, they say, never end—poverty, affordable housing, clean water, transportation, congestion, garbage. And as if that weren’t enough to keep an urban planner busy for life, the entire society, they say, is also now undergoing a worldwide paradigm shift—thanks to mobile communications and the Internet, global climate change, and a struggling economy.

The shift is towards interdependence and sharing. Consider this:

“Privacy is Already Gone”

The American Dream is focused on ownership, and since World War II, Americans have wanted to own their own houses and cars because it signals success. But perhaps the American dream made more sense in the prosperous time after World War II than it does today.

The cost of houses and cars has become prohibitively expensive, and much of it has been bought on credit. Also, a warming planet and rising levels of CO2 are causing more people to rethink driving and owning cars. Faculty say what’s beginning to matter to a growing number of Americans is not owning things. Thanks to the Internet and social media, climate change and a strained economy, a trend has emerged towards sharing. Consider, they say, house shares, car shares, bike shares, office shares, or farm shares.

“The younger generation is already sharing,” says Prof. Eran Ben-Joseph, head of the Department of Urban Studies and Planning. “Young people are sharing cars, couches, and their whole personal life online. In the future, we’ll see more sharing of personal items, like bikes and cars, not only in the U.S. but around the globe,” adds Ben-Joseph, author of Rethinking A Lot, (a book on parking lots) who says that with 600 million cars in the U.S., if all the surface lots were connected, it would cover land the size of Puerto Rico.

“A majority of people in China, India, and Brazil still live in tough conditions. And if they’re slowly rising up, increasing their economic vitality, it’s hard for them to hear our message not to invest in highways, cars, or personal goods,” he says. “They shared their resources all their lives, and now with growing personal wealth also comes personal ownership. But to sustain the planet, eventually we all will have to change and learn to share our urban resources. Hopefully, they’ll learn more quickly than we did.”

Dennis Frenchman, Leventhal Professor of Urban Studies and Planning, adds: “The information age connected us, and now we can’t go back to living our private little lives where everything belongs to only us. Our privacy is already gone.”

Piggybacking, Boston to D.C.

In this spirit, Prof. J. Meejin Yoon, along with partner Eric Höweler, developed the Shareway, a bold new vision for sharing the road in 2030. The Shareway, which won the Audi Urban Futures Award in 2012, would merge all forms of transportation on the existing I-95 Boston to Washington corridor into a single artery, piggybacked by a new high-speed rail system.

Imagine all transportation—commuter and freight trains, cars, bikes, and pedestrians—coexisting on a multi-level track to prevent traffic jams. Tracing the 400-mile route from Boston to Washington, the “BosWash” Shareway would connect to a Superhub in Newark with an airport, seaport, rail station, and interstate intersection. Also part of the plan are house-sharing programs and converting vacant land in Baltimore into agricultural fields.

“We created this project to inform people and to entice them into thinking differently. We wanted them to think about, talk about, and imagine alternative possibilities in the future,” says Yoon, adding that the sole intent of the bold design was to shift consciousness, expanding our minds to grasp a new reality.

Small is the New Big

Kent Larson has already grasped the new reality. He’s director of the City Science Initiative at the MIT Media Lab, and his group is responsible for the CityCar, which is zooming into the future at 30 mph. Designed to be shared, this stackable electric vehicle gets the equivalent of 200 miles per gallon and folds for parking to one-third the size of a regular car.

And as more people crowd into cities, the average studio apartment will shrink to 300 square feet, says Larson, whose group is also designing micro apartments to function at twice the size.

“You can effortlessly convert a two-bedroom apartment to a party space. The bed and table lift up to the ceiling, the walls move, and you’ve got one big open space in a matter of seconds,” he says, adding that small tables pop up, furniture folds out of walls, or sinks sit like shelves over the toilet. Quick-change apartments are a big plus for residents who want a shorter commute, affordable housing, and city life right outside the door, he says.

Also part of a sharing trend is shared workspaces. Rather than leasing a separate office, hundreds of startups are now renting coworking facilities all in one building. “Instead of 100 companies buying their own equipment, they share. It’s happening all over the world, and it’s a trend that just will continue,” Larson predicts.

“Breathtaking” Problems

Just as we share what is good and beneficial to our lives, we also share the problems––flooding, food distribution, rising levels of CO2. “The problems are vast,” says Adele Santos, dean of the School of Architecture and Planning, adding for example: “You can’t even breathe the air in China.”

China is choked with traffic and pollution. But when that air from China blows east, it also accounts for 20 percent of the pollution on the U.S. west coast—and that’s when just one-tenth of the Chinese own cars. What will the air be like when that number triples in the future?

“If you’re going to solve the problems of future cities, you have to have an interdisciplinary call to service,” says Santos, adding that old practices—like building sprawling, car-centric cities or building on arable land— no longer work. “Honestly, there are very few problems of this magnitude that can be solved by one discipline. The problems are huge. Breathtaking, actually. And it’s scary, because you don’t want to fail, and yet, it’s incredibly complex. We’re planning at a scale that’s absolutely unprecedented, and effectively speaking, we don’t really know how to do it. That’s the truth.”

That, she says, is precisely why this year the School launched the Center for Advanced Urbanism (CAU)—an interdisciplinary think tank that focuses on big-scale urban design problems, with 22 faculty labs collaborating on solutions.

Collective Energy

Prof. Alexander D’Hooghe, director of the Center for Advanced Urbanism, believes that MIT is a leader in cracking global problems precisely because of its expertise in crossing disciplines.

“When MIT began 150 years ago, it was by definition a model of integrating disciplines—chemical engineering, design, physics—were literally integrated into a mega structure, and it’s the way we still operate today,” he says. “Collaboration is built into MIT’s genetic material. That’s our destiny.”

On one project, he adds, CAU is consulting with four faculty from different disciplines, on another, with nine at a time. Collaborating and sharing ideas with many is great for gleaning solutions, he says, but it also carries new challenges. “In a way, it’s like being a negotiator in a foreign conflict,” says D’Hooghe, a designer and civil engineer, adding that working with multiple people, and across multiple disciplines, requires deep empathy, careful listening, and great diplomacy.

Prof. Nader Tehrani, head of the department of architecture, agrees. “We’re beginning to understand that we don’t design cities on our own desks. We’ve become a consortium, where the architect becomes a mediator, an ambassador of different disciplines. We’re now like conductors, maestros in the symphony,” says Tehrani, who understands that when many pool their minds, something marvelous happens—their collective energy becomes a force that helps solve the problem.

A generous gift from the Sherry and Alan Leventhal Family Foundation is supporting the work of the CAU for the next three years.

Decade of Design

One problem under way at the Center for Advanced Urbanism focuses on how physical design can improve human health—such as obesity, asthma, cardiovascular disease, diabetes, or depression. Called the Decade of Design: Health and Urbanism Initiative, the 10-year project is a collaboration among MIT, the American Institute of Architects, and the Clinton Global Initiative.

The very field of urban planning was born out of concern for public health, D’Hooghe says. Industrial cities were overcrowded in the late 19th century, and urban planning was a response to the crisis. Frederick Law Olmsted, for example, designed New York’s Central Park to give residents of a dirty, crowded city acres of grass for exercise and recreation. Similar is thinking of public health today.

Prof. Alan Berger, CAU’s research director, says, “In Los Angeles, city planners and transportation planners have a 30-year vision to add denser housing near major highways with highly polluted air. It may reduce commuting a bit if jobs are also nearby, but not enough to significantly improve air quality. What they overlooked is that adding more people would also likely lead to increased asthma rates or premature death, as scientists have since shown.”

The Health and Urbanism study will help identify factors that contribute to urban health, since some design guidelines are not effective nor proven, Berger says, such as the belief that people get more exercise in cities with sidewalks or that higher diabetes rates correlate with higher numbers of fast food restaurants. “Every urban setting is unique. There are no silver bullets.”

Dynamic breakthroughs in urban issues eventually will come not from one discipline or another, but from the dark zones of knowledge that lie between disciplines, he says, adding that if you work at it enough, from the darkness emerges light.

The CoLab View

Dayna Cunningham believes in shining light on everyone, because with big problems, solutions can only be holistic. “We consider people from different social positions as colleagues,” says Cunningham, executive director of MIT’s Community Innovators Lab (CoLab).

For example, poor people actually are experts on problems, from illness to dealing with life without money. Yet in a bad economy, no one asks them how they make ends meet, often because they’ve been told what they think doesn’t matter. The Lab—now working with community organizations in the U.S., Latin America, and the Caribbean—co-develops projects with people at the margins of an urban system, from energy to economic development, “because they offer tremendous insight,” she says, adding that the lab casts the poor not only as those with problems but as inventors of creative approaches.

“A whole range of judgments go with being poor, and if you have grown up marginalized, you have internalized that,” says Cunningham, who is sensitive to those whose voice is unheard, and whose own African-American great uncle—who graduated from Yale Law School—worked as a Pullman Porter, carrying bags and serving whites on trains.

“We have people—from soccer moms to police chiefs to kids in hoodies—whose life experiences are counterintuitive, whose life truths are opposite, and we put them together around the table and get them to co-create solutions.”

That, she believes, is how we will solve our problems. Another Smart car can’t heal the planet, but what may, she says, is putting together people with different kinds of experience and intelligence and learning to co-create. “You learn to make a way of no way.”

“It’s Not Me, It’s Us”

Our lives are connected. Think of fallout from Fukushima, indifferent to boundaries that divide countries. A downturn in one economy affects other economies. An oil spill in the Gulf of Mexico reverberates around the world.

The world is one. Our destiny is linked. How we survive depends on how we cooperate.

“It’s all global,” says Dennis Frenchman, who is working to stem pollution in China. “Digital technology has put a nervous system into the planet, so we can actually feel the pain in China. This is a global level of consciousness and interdependence that we just never had before.”

The shifts caused by climate change, the economy, and social media, Frenchman says, bring a new reality. “The old ways are collapsing. All these changes are interrelated, and because of the Internet, we have a different notion of privacy than our parents did. It’s becoming an inclusionary society. We are seeing small changes, then all of a sudden they will accumulate, and we’re going to see a whole new city. You may not be aware of it, but you’re living it.”

J. Meejin Yoon says perhaps these changes will also change us. If the American Dream of ownership made us greedy or competitive, perhaps a sharing society will make us more generous or caring.

“I think it will,” she says. “You need to be more generous and tolerant when you live in a city. When you compress people together, you need to be OK with noise upstairs or when a neighbor leaves a bike in the stairway. The biggest message of this shift in consciousness is—it’s not me, it’s us,” she says. “We have a sense we’re in this together, that the challenges surpass each individual.”

“We have to work together,” she says, “otherwise not only will our cities fail but we will all fail as well.”