Las Urbanistas

Wijnanda Deroo for The New York Times; The Netherlands Institute for Sound and Vision in the town of Hilversum.

The headquarters of the federal environment agency in Dessau, Germany, occupies a low-slung building on the edge of an abandoned gasworks. Dessau, a center for munitions production during the war, was virtually obliterated by Allied bombs. Over the next 50 years, East German factories saturated the soil with chemical and industrial waste. Yet both the agency building and its location might be said to embody a new, ecologically sensitive Europe.

Designed by a young Berlin-based firm, Sauerbruch Hutton, the building is touted as one of the most efficient in the world, but it doesn’t wear its sustainability on its sleeve. Four stories high, it wraps around a vast interior courtyard that is cooled and heated by a system of underground pipes. Vents in the glass roof allow hot air to escape, and an occasional breeze passes through the courtyard’s gardens. The sinuous wood structure is clad in horizontal bands of candy-colored, enameled glass panels, in shades of green, red and blue. The pattern, it turns out, is carefully tuned to the surrounding environment: the green reflects a nearby park; the red, the brick facades of an industrial shed; and the blue, the sky.

After more than a decade of tightening guidelines, Europe has made green architecture an everyday reality. In Germany and the Netherlands especially, a new generation of architects has expanded the definition of sustainable design beyond solar panels and sod roofs. As Matthias Sauerbruch put it to me: “The eco-friendly projects you saw in the 1970s, with solar panels and recycled materials: they were so self-conscious. We call this Birkenstock architecture. Now we don’t need to do this anymore. The basic technology is all pretty accepted.”

In the United States, architects cannot make the same claim with equal confidence. Despite the media attention showered on “green” issues, the federal government has yet to establish universal efficiency standards for buildings. Yet, according to some estimates, buildings consume nearly as much energy as industry and transportation combined. And the average building in the U.S. uses roughly a third more energy than its German counterpart.

Americans did not always lag so far behind; much of our most celebrated architecture has had a green strain. Frank Lloyd Wright, Rudolf Schindler and Richard Neutra all sought to create a more fluid relationship between indoor and outdoor spaces, man and nature. At the height of the cold war, architect-engineers like Buckminster Fuller envisioned marshaling the immense resources of the American military-industrial complex to create a more ecologically balanced world. Fuller’s geodesic domes, which he hoped would one day house all humanity, were cheap and lightweight yet held up in extreme weather. They could also be erected in a matter of hours. In the late 1960s and ’70s, the Whole Earth Catalogue, with its D.I.Y. ethic and living-off-the-land know-how, encouraged a whole generation to dream of dropping off the grid.

By the ’80s the green dream had faded somewhat. Faced with corporate and governmental clients who saw little financial benefit in investing in sustainable design, American architects often ignored ecological questions. The few who didn’t tended to focus on small-scale projects that could serve local populations: mud-brick construction in Arizona or rural shacks made of recycled materials in Alabama.

In Europe, by contrast, where the E.U. and national governments often play a greater role in planning and regulating building, the effort to develop sustainable architecture gathered momentum. By the mid-90s, all new construction in Europe had to meet basic requirements in energy consumption, and many European architects began to make sustainability a central theme in their work. This was true of established architects like Norman Foster, whose 1997 Commerzbank in Frankfurt was conceived as a soaring high-tech glass-and-steel tower punctuated by open-air gardens. But it was especially true of younger European architects who were just beginning to practice their craft at that time and saw sustainability as a basic moral responsibility.

Some of the early projects of this new, ecologically attuned generation had a wonderfully goofy, fairy-tale quality. There was Sarah Wigglesworth and Jeremy Till’s house, made of stacked sandbags and straw bales and topped with a meadow of wild strawberries. There was MVRDV’s Pig City, an imaginary project conceived as a grid of enormous concrete-slab towers, interspersed with stacks of lush gardens that looked as if they were suspended in midair. And there was the equally whimsical Minnaert Building, at the University of Utrecht, the Netherlands, by the Dutch firm of Willem Jan Neutelings and Michiel Riedijk, completed in 1997. Its cartoonish spray-on concrete facade is propped up on big metal letters that spell out the building’s name. Inside the cavernous main hall, tiny alcoves resembling monastic cells are embedded in the thick walls, each with its own space heater. Neutelings was inspired, he said, by the coal braziers that were once used to heat homes. Giant funnels cut out of the roof collect rainwater in a vast pond; in the summer, water is drawn from the pond into pipes in the ceiling, cooling the building.

“We experimented a lot with darkness,” Neutelings said on his first trip back to the building since it opened in 1997. “We were interested in the contrast between light and dark rather than the idea of total transparency. And we played with the idea that you can have different climates in one building, which is a much healthier working environment.”

This project was followed by another, a government tax office in Apeldoorn buried one story underground and covered by a vast reflecting pool. The surrounding subsoil — a dense mixture of sand and clay — stores heat in winter and cools the building in summer. The pool regulates the tax office’s internal temperature by absorbing excess warmth; usefully enough, it also serves as a security barrier.

“They considered surrounding the complex with very high walls and barbed wire,” Neutelings said with a mixture of humor and disgust. “They were obsessed with security. So the reflecting pools act as a gigantic moat.”

Few architects, Neutelings said, would design a building like the one in Apeldoorn today, not because sustainability has become a creative dead end but because a building no longer has to look “green” to be environmentally sensitive. “In the mid-90s clients were still very suspicious about strategies like this,” Neutelings’s partner, Michiel Riedijk, said. “Now the argument is set — there is no longer any need to prove that sustainability is important. We are technologically more advanced. So we are way more relaxed about how we express it.”

The most stirring examples of this new attitude are often found in Europe’s industrial wastelands. Standing at the edge of Rotterdam’s abandoned piers, many of which will soon become sites for high-end housing, Neutelings proudly ticked off the city’s credentials as a capital of environmental waste: most of England’s industrial air pollution, he tells me, is carried here by the north winds. Historically, Germany’s industrial waste flowed down the Rhine to be deposited in Rotterdam’s harbor. “We are the main collecting point for all of Europe’s pollution, its garbage dump,” he said with a smile.

Like many of his contemporaries, Neutelings doesn’t see this landscape as ugly. Nor does he see the creation of bold industrial forms and a sustainable environment as necessarily in conflict. Neutelings and Riedijk’s recently completed Shipping and Transport College, which rises at the edge of an aging industrial pier, looks perfectly at home. The building’s cantilevered top evokes a gigantic periscope; its corrugated metal skin brings to mind the stacked shipping containers still scattered around the port. The thick heavy walls retain heat and cold, while inside, the escalators are set to move slowly to conserve energy, their low hum mimicking the sound of nearby ships.

UNStudio’s Mercedes-Benz Museum in Stuttgart also rises in the shadow of industry. Overlooking the company’s administrative offices and test track, its spiraling aluminum-clad exterior is seemingly built for speed. Inside, intertwining ramps that echo the elevated freeway outside lead from one floor to the next. The museum is a testament to how much green architecture has changed: its towering central atrium is both an architectural tour de force and a part of a sophisticated ventilation system. Rather than recycle used air, as buildings that depend on old air-conditioning systems do, the museum’s thick concrete walls store hot and cool air, which is then drawn into the atrium. Were the museum to catch fire, the atrium’s ventilation system would create a sort of mini-tornado to suck out the smoke.

In a pastoral setting, the gorgeous cast-glass facade of Neutelings and Riedijk’s Netherlands Institute for Sound and Vision masks an efficient ecological machine. Built to house the Dutch television and radio archives, the center’s galleries and offices are insulated from extreme weather by a facade of double glass panels. The archives themselves are buried in underground vaults — the surrounding earth is used to cool the warren of storage rooms. The building is split into two climatic zones, not just to save energy but to reinforce the experience of two different environments: the dark world of the underground vaults, which the architects dubbed the inferno, and the twinkling, light-filled world above.

Neutelings was quick to note that a building’s efficiency should be measured not just by its mechanical systems but also by how much energy it uses over its lifetime. More energy is expended in a building’s construction than at any other stage, so a structure that lasts 100 years will use far less energy than one that lasts 5, no matter how efficient.

“From this point of view the Pyramids are the most sustainable buildings in history,” he said.

For now, the United States has no federal regulations that would guarantee a minimal level of sustainability in new construction — or spur an ecologically attuned approach to new architecture. The LEED guidelines, which were drawn up by the U.S. Green Building Council, a nonprofit group founded in 1993, are a voluntary program that is now more than a decade old. Even when they are adhered to — they’ve been adopted by a number of government agencies, most notably the General Services Administration , which oversees the construction of federal buildings — they still have little effect on the majority of commercial or residential construction. In most cases, the decision to make an efficient building still rests with the client.

What’s more, the guidelines often lead to a constricted idea of what sustainability means. “In Europe the guidelines tend to have to do with broader organizational ideas,” Thom Mayne, the founder of the Los Angeles-based architectural firm Morphosis, told me. “Energy consumption, the organization of the workplace, urbanism — they’re all seen as interlinked. Here, the whole focus is on how to get these points. You just check them off: bike racks, high-efficiency air-conditioning units — it’s very narrow.”

Stefan Behnisch, an architect who has long been considered a leader in sustainable research and has worked in both Europe and the United States, agrees. “The problem is that these ideas become clichés,” he says. “They don’t allow for anything interesting and new. They rule out real invention.”

There are, nonetheless, some significant, innovative projects in the United Sates. Norman Foster’s new Hearst Tower in Manhattan has many of the sustainable features he began exploring in the Commerzbank in Frankfurt, like natural ventilation and high-performance glass that deflects heat. And the San Francisco Federal Building, completed this year by Morphosis, looks as if it could have been assembled in Germany: the building’s narrow width gives everyone access to natural light and ventilation, operable windows let in fresh air, elaborate shading devices filter sunlight. “In San Francisco,” Mayne told me, “we didn’t even bother to go after the LEED ranking because it doesn’t necessarily lead to the most efficient building.”

But architects who choose to be inventive often find that the slightest deviation from the norm is fiercely resisted. Mayne relates how some federal workers at his San Francisco building mocked the idea of office-building windows that could be opened and closed, arguing that birds would nest on their desks while they were away over the weekend. Bloggers, meanwhile, claimed that some government bureaucrats had to wear sunglasses indoors because of the amount of natural light. Mayne countered that the shades have yet to be installed. To be sure, it is not just Americans who resist seeing a building as an integral part of the environment. Sauerbruch and his partner, Louisa Hutton, told me that workers at the environment agency in Dessau — long in the habit of toiling in sealed, air-conditioned buildings — often forget to close their windows when they leave the office. Apparently, many of them still find the effort a nuisance.

Will America ever catch up with Europe’s impressive green record? Mark Wigley, the dean of Columbia’s graduate school of architecture, has noticed a sea change in how students here approach sustainability. Increasingly, he said, they see it as a central aspect of their work. “Today’s students are an entirely different species,” Wigley said. “They’re used to absorbing inputs from about 15 different directions at once. And they’re all interested in a radical ecological point of view.”

At the same time, Wigley admits that architects cannot accomplish anything without willing clients. “My prediction is that if we have a change in America, it won’t be driven by politicians or architects but by the developers,” he said. “We’re at the moment where developers can gain a significant advantage if you reduce energy. For the first time you have clients who are willing to pay for this. So I think the one group we associate most with greed and inefficiency, it will lead the way in the future.”

Simon Norfolk for The New York Times; The Wire Opera House (1992), completed in about two months under the guidance of Curitiba’s visionary architect-mayor, Jaime Lerner.

On Saturday mornings, children gather to paint and draw in the main downtown shopping street of Curitiba, in southern Brazil. More than just a charming tradition, the child’s play commemorates a key victory in a hard-fought, ongoing war. Back in 1972, the new mayor of the city, an architect and urban planner named Jaime Lerner, ordered a lightning transformation of six blocks of the street into a pedestrian zone. The change was recommended in a master plan for the city that was approved six years earlier, but fierce objections from the downtown merchants blocked its implementation. Lerner instructed his secretary of public works to institute the change quickly and asked how long it would take. “He said he needed four months,” Lerner recalled recently. “I said, ‘Forty-eight hours.’ He said, ‘You’re crazy.’ I said, ‘Yes, I’m crazy, but do it in 48 hours.’ ” The municipal authorities were able to accomplish it in three days, beginning on a Friday night and installing paving, lighting, planters and furniture by the end of the day on Monday. “Being a very weak mayor, if I start to do it and take too long, everyone could stop it through a juridical demand,” Lerner went on to explain. “If they stop the work, it’s finished. I had to do it very fast, at least in part. Because we had discussed it a great deal. Sometimes they have to have a demonstration effect.”

Simon Norfolk for The New York Times; A station on Curitiba’s rapid-transit-bus system.

Simon Norfolk for The New York Times; Curitiba’s rapid-transit buses can move 36,000 passengers an hour, a cheap alternative to a subway system.

Simon Norfolk for The New York Times

Despite its development as a city for public transportation, Curitiba is said to have more cars per capita than any other city in Brazil.

The demonstration worked. Within days, impressed by the increase in their business, the once-recalcitrant shop owners were demanding an extension of the traffic-free district. Some diehard motorists, however, sulked. Lerner heard that a group of them were planning to disregard the prohibition and drive their cars into the street on a Saturday morning. So he contrived an unbreachable defense. With the cooperation of the city’s teachers and a donation of rolls of newsprint and boxes of paint, on that morning he assembled several hundred children in the street, where they sat and drew pictures. “It was to say, ‘This is being done for children and their parents — don’t even think of putting cars there,’ ” he told me. The sputtered-out protest was the last resistance to the pedestrianization of the shopping area, which has since expanded from the original 6 blocks to encompass about 15 today. “Of course, this was very emblematic,” Lerner recounted. “We were trying to say, ‘This city is not for cars.’ When many mayors at the time were planning for individual cars, we were countervailing.” He observed that it was emblematic in another way also: “From that point, they said, ‘If he could do this in 72 hours, he can do anything.’ It was a good strategy.”

An opening salvo, the creation of the pedestrian zone inaugurated a series of programs by Lerner and his colleagues that made Curitiba a famous model of late-20th-century urban planning. In the early 1970s, when Brazil was welcoming any industry, no matter how toxic its byproducts, Curitiba decided to admit only nonpolluters; to accommodate them, it constructed an industrial district that reserved so much land for green space that it was derided as a “golf course” until it succeeded in filling up with major businesses while its counterparts in other Latin American cities were flagging. Through the creation of two dozen recreational parks, many with lakes to catch runoff in low-lying areas that flood periodically, Curitiba managed, at a time of explosive population growth, to increase its green areas from 5 square feet per inhabitant to an astounding 560 square feet. The city promoted “green” policies before they were fashionable and called itself “the ecological capital of Brazil” in the 1980s, when there were no rivals for such a title. Today, Curitiba remains a pilgrimage destination for urbanists fascinated by its bus system, garbage-recycling program and network of parks. It is the answer to what might otherwise be a hypothetical question: How would cities look if urban planners, not politicians, took control?

Although the children who paint on Saturday mornings are no longer needed to protect the downtown shopping street from cars, the battle to keep Curitiba green is never-ending. Indeed, some say it is going badly these days. The rivers, once crystalline, reek of untreated sewage. The bus system that has won admirers throughout the world appears to be nearing capacity; what’s more, Curitiba, by some measures, has a higher per capita ownership of private cars than any city in Brazil — even exceeding BrasÃlia, a city that was designed for cars. Curitiba’s garbage-recycling rate has been declining over the last six or seven years, and the only landfill in the municipal region will be full by the end of 2008. Jorge Wilheim, the São Paulo architect who drafted Curitiba’s master plan in 1965, says: “When we made the plan, the population was 350,000. We thought in a few years it would reach 500,000. But it has grown much bigger.” The municipality of Curitiba today has 1.8 million people, and the population of the metropolitan region is 3.2 million. “I know the plan of Curitiba is very famous, and I am the first to enjoy it, but that was in ‘65,” Wilheim continues. “The metropolitan region must have a new vision.”

It is often said of Curitiba that it doesn’t feel like Brazil. Depending on who’s speaking, that can be intended as a compliment or a criticism. Populated by European immigrants in the 19th century, Curitiba has a demographic makeup that is largely more fair-skinned and well educated than that of Brazil’s tropical north. It is also unusually affluent. Unlike São Paulo, with its startling extremes of wealth and poverty, much of Curitiba to an American eye looks familiarly middle class. Even the scruffy used-car lots have a seediness reminiscent of Los Angeles, not the Rio de Janeiro of “City of God.” The city, especially the large downtown, is very clean, thanks to municipal sanitation trucks and the freelance carrinheiros, or cart people, who pick up trash to sell at recycling centers.

During my visit to Curitiba in March, the city was the host of an international biodiversity conference. While I hadn’t known of it when I scheduled my trip, the coincidence was about as remarkable as finding a design show to greet you in Milan or a wine festival under way in Bordeaux. Environmentalism is the heart of Curitiba’s self-identity, and the municipal government is always devising new schemes that showcase the brand. The rest of the world has caught on, if not yet caught up. Ecological awareness is architecturally trendy. This year’s winner of the prestigious Pritzker Prize is Richard Rogers, a longtime proponent of mass transit, lower energy consumption and ecologically sensitive buildings. Commercially, real-estate developers from Beijing to Santa Monica are brandishing their LEED certificates (Leadership in Energy and Environmental Design) as they market condominiums and office suites to green-minded consumers. While it is unusually ambitious, the 25-year plan that Mayor Michael R. Bloomberg proposed last month for New York is part of an international wave of recognition that cities must live more responsibly, especially when it comes to their effusions of climate-warming gases and their excretions of mountains of solid waste. Bloomberg’s most contentious idea — a “congestion tax” on cars entering traffic-clogged districts during peak hours — has been working for more than four years in London (and more than 30 years in Singapore) to increase the numbers of people using public transportation. Interestingly, Curitiba adopted an opposite approach, brandishing a carrot instead of a stick. The city planners suspected that public transportation would attract more users if it was more attractive. And that reasonable assumption turned out to be correct.

The efficient buses that zip across the Curitiba metropolitan region are the most conspicuously un-Brazilian feature of the city. Instead of descending into subway stations, Curitibanos file into ribbed glass tubes that are boarding platforms for the rapid-transit buses. (The glass tubes resemble the “fosteritos” that Norman Foster later designed for the metro in Bilbao, Spain.) Curitiba has five express-bus avenues, with a sixth in development, to allow you to traverse the city with speedy dispatch. In the early 1970s, most cities investing in public transportation were building subways or light-rail networks. Curitiba lacked the resources and the time to install a train system. Lerner says that compared with the Curitiba bus network, a light rail system would have required 20 times the financial investment; a subway would have cost 100 times as much. “We tried to understand, what is a subway?” he recalls. “It has to have speed, comfort, reliability and good frequency. But why does it have to be underground? Underground is very expensive. With dedicated lanes and not stopping on every corner, we could do it with buses.” Because widening the avenues would have required a lengthy and costly expropriation process, the planners came up with a “trinary” system that embraced three parallel thoroughfares: a large central avenue dedicated to two-way rapid-bus traffic (flanked by slow lanes for cars making short local trips) and, a block over on each side, an avenue for fast one-way automobile traffic.

When the bus system was inaugurated, it transported 54,000 passengers daily. That number has ballooned to 2.3 million, in large part because of innovations that permit passengers to board and exit rapidly. In 1992, Lerner and his team established the tubular boarding platforms with fare clerks and turnstiles, so that the mechanisms for paying and boarding are separated, as in a subway. To carry more people at a time, the city introduced flexible-hinged articulated buses that open their doors wide for rapid entry and egress; then, when the buses couldn’t cope with the demand, the Lerner team called for bi-articulated buses of 88 feet with two hinges (and a 270-passenger capacity), which Volvo manufactured at Curitiba’s request. Comparing the capacities of bus and subway systems, Lerner reels off numbers with a promoter’s panache. “A normal bus in a normal street conducts x passengers a day,” he told me. “With a dedicated lane, it can transport 2x a day. If you have an articulated bus in a dedicated lane, 2.7x passengers. If you add a boarding tube, you can achieve 3.4x passengers, and if you add double articulated buses, you can have four times as many passengers as a normal bus in a normal street.” He says that with an arrival frequency of 30 seconds, you can transport 36,000 passengers every hour — which is about the same load he would have achieved with a subway.

Unfortunately, the trends of bus usage are down. While the system has expanded to cover 13 of the cities in the metropolitan region, charging a flat fare that in practice subsidizes the trips of the mostly poorer workers who live in outlying areas, bus ridership within the Curitiba municipality has been declining. “We are losing bus passengers and gaining cars,” says Luis Fragomeni, a Curitiba urban planner. He observes that, like potential users of public transport everywhere, many Curitibanos view it as noisy, crowded and unsafe. Undermining the thinking behind the master plan, even those who live alongside the high-density rapid-bus corridors are buying cars. “The licensing of cars in Curitiba is 2.5 times higher than babies being born in Curitiba,” he says. “Trouble.” Because cars are status symbols, attempts to discourage people from buying them are probably futile. “We say, ‘Have your own car, but keep it in the garage and use it only on weekends,’ ” Fragomeni remarks. And the public-transport system must be upgraded continuously to remain an appealing alternative to private vehicles. “That competition is very hard,” says Paulo Schmidt, the president of URBS, the rapid-bus system. During peak hours, buses on the main routes are already arriving at almost 30-second intervals; any more buses, and they would back up. While acknowledging his iconoclasm in questioning the sufficiency of Curitiba’s trademark bus network, Schmidt nevertheless says a light-rail system is needed to complement it.

When it comes to modifying human behavior, persuading urban dwellers to sort their garbage can be harder than coaxing them to garage their cars. Lerner and his allies have claimed that they have succeeded beyond the dreams of environmentalists in far more eco-friendly countries, including Japan and Sweden. Curitiba was a pioneer in separating recyclable materials, with its “Garbage That Is Not Garbage” program, inaugurated in 1989. (The city leaders have a flair for slogans.) Recycling has assumed a new urgency, because the entire metropolitan area contains only one landfill, and it will be exhausted by the end of next year. José Antonio Andreguetto, Curitiba’s secretary for the environment, told me that 22 percent of the city’s garbage is being separated for recycling, a rate that has been declining over the last half-dozen years; he says he hopes to bring the number up to 34 percent by the end of the current mayor’s term in 2008. Lerner says the numbers have been eroding until recently because some recent mayors haven’t emphasized the issue, but he maintains that the recycling rate in Curitiba is still the highest in the world.

It is very hard to determine how accurate the estimates are for garbage separation. “Curitiba began early to look at recycling garbage — that is true, and it is good,” says Teresa Urban, a local journalist and environmental activist. “But the separation of recycled garbage is a little part of all the garbage we have here. There is no tradition of participation here. The mayor sold to the people the idea that this is a wonderful city. And the people think, This is wonderful, I don’t have to do anything.”

Like other left-wing critics, Urban traces the lack of participation to an original sin. The progressive urban planning of Curitiba was not initiated by a democratic process; it was set in motion by the military dictatorship that seized power in 1964 and ruled Brazil until the mid-’80s. Its environmentalism is rooted in authoritarianism. “They didn’t have to confront the public through public participation, and the decisions could be made by urban planners — architects acting as politicians,” says Clara Irazábal, who has written a book comparing the urban planning experiences of Curitiba and Portland, Ore. The city that has been called the most forward-looking in the Western Hemisphere is an outgrowth of an era that many Brazilians prefer not to look back on. Jaime Lerner, the archangel of the Curitiba green movement, was anointed by the dragons of war.

Always an anomaly, Curitiba became a model for our day by defying the spirit of the time. In the late 1950s and early 1960s, urban developers throughout the world, influenced by Le Corbusier and his followers, were remodeling cities to facilitate the easy circulation of people in automobiles. But in Curitiba, an informal group of young architects, urban planners and civil engineers at the city’s Federal University of Paraná, which is the oldest university in Brazil, objected more effectively to the mayor’s widening of streets and a proposed highway bypass that threatened the historic city center. As luck would have it, one of these outraged civil engineers, Fanchette Rischbieter, was married to the chairman of the government-controlled investment company that was financing the construction of roads in Paraná, the largely agricultural state of which Curitiba is the capital. “I said, ‘It doesn’t make sense, my wife and her friends are against these people — why don’t we make a plan?’ ” Karlos Rischbieter recalls. Selected by the city, Jorge Wilheim came up with a master plan that concentrated high-density construction along two long rapid-transit axes that skirted the center. At least as important as his transportation and zoning recommendations was Wilheim’s request for an urban-planning institute to implement them. In retrospect, the enthusiastic and talented staff of the Institute of Urban Research and Planning of Curitiba, which is known by its Portuguese acronym, Ippuc, ensured the success of Curitiba’s redevelopment.

Still, there was a lag of five years from the formal adoption of the master plan in 1966 until its implementation, which began with the governor’s selection of Lerner, who was president of Ippuc, to be mayor in 1971. Wilheim the planner needed Lerner the doer to turn abstract ideas into inventive reality. Curitiba has been studied more than copied (one notable exception is a Curitiba-style bus system in Bogotá, Colombia) because unlike Lerner, most mayors stumble over political obstacles. “I always tell a story of the ’80s,” Rischbieter says. “A friend from São Paulo came with his wife and son to visit Curitiba. He did not know this city. I took my car and showed him Curitiba for three hours. When I left him at the hotel, he said, ‘What did you show people before Jaime Lerner?’ “

A spark plug of ideas, Lerner, the son of Jewish immigrants from Poland, combines salesmanship and pragmatism. Following his mayoral terms, he won election twice as governor of Paraná State, retiring in 2002 at the age of 65 to devote himself to his architecture firm and to worldwide speaking engagements espousing green urban planning. He has a large head that seems to rest directly on wide shoulders; knowing his passion for recycling, you might almost believe that his thick-set body has been through a compactor. He radiates a highly compressed and infectious energy, with a can-do assertiveness that borders on arrogance. “He never asked if something was good or not,” Rischbieter remarks. “He would say, ‘I’ll go do it.’ I would say, ‘You have to go ask people and get their opinions.’ He would say, ‘No, they won’t agree with me, and it has to be done.’ He is not a political animal, he is a dictator.” Rischbieter admires Lerner; others, however, using the same descriptive terminology, do not. In the rough-and-tumble of Brazilian politics, it has become customary for supporters of populist parties to disparage Lerner (who personifies his talented team to allies and foes alike) as a creature of the dictatorship. According to this argument, the generals detested politicians; they admired technical experts. In Curitiba, they found a showplace to display their accomplishments to the world. “The military are addicted to planning,” says Fragomeni, who has an ambivalent attitude toward Lerner. “If they don’t plan, they don’t go forward. They invested in Curitiba. Mr. Lerner may like it or not. His continuity was ensured by the military government.” For his part, Lerner says that he had a far harder time with the military dictatorship than he did later, as an elected official. Under the military regime, he served at the pleasure of the governor and the state assembly. “I could be fired the next day,” he says. “Being an elected mayor, I was stronger. Nobody could fire me.”

In two terms (1971-75 and 1979-83) under the military regime, and then in an elected third term (1989-92) after the restoration of democracy, Lerner translated the master plan into concrete and leafy reality. Like an impatient muralist, he worked on a wide scope at high speed. “I know cities that plant 10,000 trees, and they make a whole festival,” he told me. “We planted a million trees. I am obsessed with scale.” He sought to make a livable city; over time that segued smoothly into an ecological city. Parks initially intended as recreational areas would also absorb floodwaters and extract carbon dioxide from the atmosphere. Lerner used tax breaks to wheedle landowners into turning over portions of their property, which typically had little value at the time. In the rocky northern district, he converted one flooded quarry into the Wire Opera House, which has become a city icon, and another into the Free University of the Environment, a non-degree-granting institution that educates people on ecological issues. He transformed land that was serving as a refuse dump into a botanical garden; named for Fanchette Rischbieter, who died in 1989, it features a duck pond, French parterres and a classic Victorian greenhouse. The architecture in all three of these parks is less noteworthy for its formal design than for its building materials — salvaged telephone poles, mesh grating, metal tubing — and the speed of construction. From blueprint drafts to opening night, the Wire Opera House took about two months to complete. Lerner refers to such projects as “urban acupuncture” that energizes the development process.

When I would ask people if they thought Lerner could have accomplished his reforms under a democracy, people sympathetic to both Lerner and the military (like Rischbieter) or critical of both (like Urban) would say no; but most, professing admiration for Lerner but distaste for the military, said the dictatorship was not a precondition for his success. Lerner and Wilheim were emphatic on this point. “Not being a traditional politician helped me a lot,” Lerner told me. Nonetheless, by entering public life, even a self-professed apolitical man becomes a political actor. What struck me was the way in which the return of democracy changed Lerner’s core constituency. Under the generals, he was vulnerable mainly to the business community. That is why, for instance, he had to implement the pedestrian mall so quickly: if the business class lost confidence in him, the state assembly would have insisted that he be replaced. In a democratic Brazil, Lerner and his successors are threatened not just by the rich, but perhaps even more acutely by the poor — politically, by populist parties, and demographically, by the inexorable population growth. In politics, the pendulum has swung, as it always does. For the first time in 15 years, the winning candidate in Curitiba’s last mayoral election, in 2004, was not directly associated with the Lerner Group, the firm of 10 architects and planners that Lerner runs. Still, the new administration is continuing on the path that Lerner blazed. More worrisome for Curitiba’s future is the demographic trend. Over the past half-century, the state of Paraná underwent a radical change, from a labor-intensive coffee economy to a mechanized agriculture of soybeans. Hundreds of thousands lost their jobs. Many of the dispossessed have relocated to the Curitiba metropolitan region, which in Brazil is famously livable. Every day, more keep coming.

The “invasions” of homeless people onto unoccupied land spill like ink stains over the neatly outlined development maps of the urban planners, not only in Curitiba but across Brazil. One Saturday morning, I visited the neighborhood of Nossa Senhora da Luz, where a small group of people waited with sacks or improvised carts of garbage. The hardscrabble community dates from an early invasion of the 1970s. Today the streets are paved and the houses are solid cinder block, but unlike downtown Curitiba, here it is immediately apparent from the bleak, scrubby streetscape and the dark skins of the populace that you are in a third-world setting. I was there to observe one of 79 exchange centers that the municipality of Curitiba has established in communities where the streets are too narrow or too bumpy for large garbage trucks to circulate. Instead, people can carry their trash to biweekly collection sites and trade four pounds of garbage for one pound of vegetables. Mostly they bring plastic, paper and cardboard. At another site, run by the community council, more valuable aluminum cans are collected in return for money, and at yet another, organic material is traded for bus tokens. Compared with middle-class people, the residents of this neighborhood do not generate so much recyclable material; much of what they trade they prospect for around the city. Curitiba may be more successful in enlisting poor citizens to function as part-time carrinheiros than in enlightening better-off residents on their civic responsibilities.

The largest working-class housing development within Curitiba is called Bairro Novo, or “new neighborhood.” It was developed hurriedly, you might say frantically, after a band of 3,000 people, at the start of a three-day holiday weekend in September 1992, invaded a nearby parcel of vacant land where a disused railroad line once operated. This was the same sort of stealth tactic that Lerner employed two decades earlier to pedestrianize the shopping street, but now it was being used against him — coordinated, he maintains, by his political opponents, who controlled the governorship then as they do now. Since the security forces are directed by the state of Paraná and not the city, there was no way Lerner could stop the so-called Ferrovila (or railroad town) invasion. He says that he was especially infuriated because his administration had been researching the creation of a much larger development on the same land, housing 10 times as many people, as well as establishing schools and other social services. Instead, his team began planning the Bairro Novo on a parcel of land that was slated for development a decade or two later. There are 80,000 people living in Bairro Novo today. For a while, the illegal squats died off. “If you have a good alternative, you can prevent the invasions,” Lerner says.

Recently, invasions have started up again. “There is a feeling that it may be politically motivated,” says Fragomeni, the urban planner, who served until March as president of Ippuc. He reports that in Curitiba today, there are 13,000 households in invasion settlements, 6,000 of them in ecologically fragile areas. Squatters often occupy land by rivers, both to obtain a water source and because, by law, the riverbanks can’t be developed. “The land is forbidden, and it is free at the same time,” says Urban, the environmental activist. Raw sewage from these settlements flows directly into the rivers. Fragomeni says that fewer than 70 percent of Curitiba households have sewer connections. The current administration, led by Mayor Beto Richa (who was endorsed by Lerner but is not professionally associated with him), is trying to alleviate the problem with a new program to clean up the water basin of the sadly polluted Bariguà River: relocating people to housing that is a little farther from the river, replanting vegetation on the banks and linking houses to the sewage system.

The program to reclaim the Bariguà basin was galvanized by the most recent invasion in February, when 1,500 people seized land near Ferrovila in Bariguà Park and hit a sensitive nerve. Their encampment is provocatively close to Ecoville, a controversial upper-middle-class development that arose in the mid-’90s along one of the rapid-bus corridors. As Lerner acidly observes of Ecoville, “I don’t like this project, because it is not ‘eco’ and it is not ‘ville.’ ” Ecoville is a self-contained development in which tall buildings loom over patches of vegetation and looping roads. It’s an unconvincing version of the discredited Corbusian model of “the city in the park,” an idea that the developers self-consciously reference by naming one of these buildings “Le Corbusier.” Many buildings have been labeled for works by Picasso — the Arlequin, the Pierrot, even the Guernica. One noteworthy Picasso-christened tower, the Suite Vollard, features 11 full-floor residences, each of which is supposed to be able to rotate independently. The Suite Vollard is 10 years overdue for occupancy. Its engineering is still unproved.

Ferrovila and Ecoville: in close proximity, you can see the politicized landless and the profit-minded land developers who threaten Curitiba’s status as an ecological city. A reputation can be as hard to uphold as to establish. Unlike his three immediate predecessors, Mayor Richa — a boyish, blow-dried 41-year-old civil engineer from a prominent political family — is not an urban planner. And Ippuc, while still powerful, no longer directs the show. Richa has discontinued the longstanding mayoral custom, established by Lerner, of attending a weekly meeting at Ippuc. Under Lerner and his successors, “the mayor sat in Ippuc, and you felt what he wanted,” Fragomeni says. “It was a very verticalized government. Ippuc also planned the budget for the city. There’s democracy now, which is good. But it is no longer a pyramid; it’s a network. The mayor now expects you to propose what Curitiba should look like. He’s not a town planner.”

Nor is Curitiba a single town any longer. It’s a conurbation. Planning must be for the metropolitan region, not just for the municipality. Does it matter that Curitiba bans polluting industries if the neighboring town of Araucária has an oil refinery belching smoke on the city line? Similarly, if the new immigrants to the poor surrounding communities don’t recycle, then Curitiba’s landfill, the only such facility in the metropolitan region, will fill up even sooner. Like garbage, water does not respect city limits: Curitiba’s water supply depends on reservoirs controlled by municipalities outside its borders. What was never simple has become even more complex. For a long time, the citizens of Curitiba were so proud of the city’s reputation as an urban showplace that they kept re-electing urban planners — self-styled technical experts who seemed to be above politics and who vaunted their expertise in running the buses, building the parks and recycling the garbage. But a mayor today must be able to negotiate successfully with other mayors if reform is to work. Mayors need to be politicians, even in Curitiba.