In an acrylic tube submerged in the Indian Ocean, at Hilton Hotels’ Ithaa Restaurant, in the Maldives, diners are also surrounded by fish and coral as they eat. Although the Maldives, a nation of islands only five feet above sea level, emits but a tiny fraction of the world’s pollution, its president, Mohamed Nasheed, has set the most ambitious climate goals of any country on Earth, promising to go carbon neutral within ten years, while building sustainable hotels and restaurants and even a floating golf course. “Our oil-fired power stations will be replaced with solar, wind, and biomass plants,” Nasheed explains. “Our waste will be turned into clean electricity through pyrolysis technology, and a new generation of boats will slash marine transport pollution. By 2020, the use of fossil fuels will be virtually eliminated in the Maldivian archipelago.” Greening the economy is good for the Maldives, which has begun attracting a flock of eco-tourists and investors, and it’s also a model for changes radical enough to help fix the climate.

  In some cities, coexisting with nature means salvaging rusty old infrastructure, reclaiming abandoned blocks and trashyards, and forging junked metal into inviting habitats for plants, animals, and humans. In every U.S. state, and many other countries from Iceland to Estonia, Australia, and Peru, out-of-work railroad tracks have morphed into peaceful “rail trails” ideal for biking, hiking, and cross-country skiing. Most often they slip through towns or skirt farmlands, drawing both humans and wildlife to leafy byways. I’ve biked or cross-country skied on some beauties in Ohio, California, Arizona, and New York. Memorably, biking on a rail trail outside Gambier, Ohio, at dawn, I was chased by a flock of farm geese. I knew their charge was merely bravado, so I pedaled slowly and let them nip at my pant legs, which seemed to give them a sense of territorial satisfaction, and they soon returned to the barnyard. I enjoyed their brief honking companionship, and learned something about geese I didn’t know: what clamorous watchdogs they make.

  A different stripe of oasis growing in popularity is the High Line on Manhattan’s West Side, a surprising sprawl of undulating benches, nests, perches, and lookouts, giving New York City yet another bridge—this one between the urban and the rural. An old elevated freight spur, little more than a rusty eyesore on the Hudson, it’s metamorphosed into a tapestry of self-seeding wildflowers and domestic blooms. It isn’t the first raised park (there’s the Promenade Plantée in Paris, and remember the Hanging Gardens of Babylon?), but the High Line is the loveliest city rail trail I know.

  Picturesque, with many scenic views, it’s also richly detailed and alive, allowing you to feel elevated in spirit, floating in a garden in space where butterflies, birds, humans, and other organisms mingle. In a practical sense, it’s a lofty shortcut, a sky alley that avoids all the intersections. A million people have already strolled its landscaped corridors, and it’s inspired other cities hoping for similar sky parks. Chicago, Mexico City, Rotterdam, Santiago, and Jerusalem are among those following suit with their derelict trestles, each an urban renewal project featuring regional plants and its own special character or sense of humor. In Wuppertal, Germany, the rails-to-trails corridor includes a brightly colored LEGO-style bridge. Like the wastewater wetlands, such projects are widening our notion of recycling and yielding an urban lifestyle that’s interwoven with nature.

  As one salve in our medicine cabinet of good ideas, these vest-pocket urban parks and wildlife corridors have deep roots around the world, from nest boxes for storks in Romania, Switzerland, Poland, Germany, Spain, and other havens along their well-flapped migration routes to species-rich Central Park in the heart of New York City, London’s eight city parks (in several of which deer roam), the temperate rainforest of Vancouver’s Stanley Park, Moscow’s Losiny Ostrov (“Moose Island”) National Park, Sanjay Gandhi National Park in Mumbai, sod roofs and greenways from Germany to the Faroe Islands, St. Luke’s Hospital rooftop garden in Tokyo, mandatory rooftop gardens in Copenhagen (and proposed in Toronto). A surprising jumble of native species thrives in and around heavily planted Rio de Janeiro, Istanbul, Cape Town, Stockholm, and Chicago, which have become biodiversity hotspots. Then there’s Singapore’s big, blooming, downtown Gardens by the Bay, enriching city life with more than 240,000 rare plants, flowers, and trees in domes that rise sixteen stories over the city. Including a cloud forest and aerial walkways, the gardens collect rainwater, generate solar electricity, and bathe the air. Opening on June 29, 2012, they drew 70,000 nature-hungry visitors during the first two days.

  Although these new city oases won’t work for all species, or for all communities, the trend for rewilding our cities is growing. It’s positive, it enlightens, it’s widespread, and it helps. We need to retrofit and reimagine cities as planet-friendly citadels. They’re our hives and reefs. Sea mussels aren’t the only animals living in individual shells that are glued together.

  A GREEN MAN

  IN A GREEN SHADE

  As a child, Patrick Blanc loved going to the doctor’s office. A six-foot-long aquarium in the waiting room tickled his eyes with colorful tropical fish and plush green plants that swayed in the current and beckoned like hands. To an urban boy growing up in the Parisian suburbs, it offered a glimpse of paradise. When he put his ear to the small box attached to the aquarium, he heard the bubbling of water through tubes and the filter’s hum. The hydraulics and engineering intrigued him as much as the fish, and before long he designed his own small aquarium at home. For a spell, he also adopted coral-beaked waxbills, setting them free on Thursday and Sunday mornings to fly around the apartment.

  As he entered adolescence, his nomadic curiosity drifted from aquariums and birds to aquatic plants, and then, at fifteen, he leapt above the waves to the world’s moist shaded zones, the mysterious understory of tropical forests. A college trip to the rainforests of Thailand and Malaysia brought the revelation that “plants could sprout at any height, not merely from the ground.”

  Now a bounty of planted walls refreshing cities around the world owe their design or inspiration to Blanc’s eco-pageants, and lure birds, butterflies, and hummingbirds while they mutate with the seasons.

  One of Blanc’s personal favorites, a green city icon, is the magnificent Quai Branly Museum in Paris, which opened in 2006 and was greeted by many as a botanical epiphany. Multitextured meadows climb the thirteen-thousand-square-foot facade of the building, more than half of which is alive. The rest is windows, creating a giant plaid of thick-leafed, mossy, breathing wall, touchably soft, rich with scent, atwitch with birds.

  Cloaking the facade in great variety to reflect the cultural diversity of the world’s artists, Blanc chose a pastiche of species from temperate zones in North America, Europe, South America, Asia, and Africa. He would have included Oceania, but tropical plants can’t survive the Paris winters, and the facade—which is part botanical tapestry, part hidden lagoon, and entirely soil-free—is intended to endure for many years, filling the senses of Parisians, and building a 40-foot-tall, 650-foot-wide ecosystem amid the hard premises of city life, while also helping to purify the air and eliminate carbon dioxide. In warm weather, flowers bloom, butterflies nectar, and birds perch and nest in the dense thickets. One half-expects to find miniature deer browsing on its mossy hillocks. The museum director plans on adding frogs and tree lizards. Because our horizontal indoor life can flatten the mind, some of the administrative offices also have smaller vertical gardens, which are visible through the windows, blurring the line between outside and inside even more.

  How can a towering garden with a northern exposure survive the icy winds sweeping across the Seine? That’s where Blanc’s education and research as a botanist come in. The living wall is hardy because he’s chosen hundreds of understory species that he’s discovered can nonetheless tolerate slathers of direct light and wind.

  “When I think of Heuchera,” he says, referring to a family of plants that includes coral bells and alumroot, which produce small delicate flowers, and whose leaves are like hands with the fingers extended, “I always
think of their leaves emerging intact from the melting snow in April, along the steep slopes in the shade of giant sequoias in California.”

  Blanc works with a palette of deep rich greens in dozens of subtle shades and intensities, from asparagus and fern green to forest or praying mantis green, and textures that run the gamut from matte to hairy, spongy to sheen. All vary with time of day, age, season, clouds eclipsing the sun, fog rolling off the river, rush-hour traffic, aberrations of twilight. Seen through our rods and cones, the colors remix and evolve perpetually as they would if we encountered them in a forest. He prefers leaves to flowers, doesn’t care for trailing vines, and is sensitive to the architecture of leaves. The thousands of individual plants he quilts together grow leaves that are bristled, pointed, star-shaped, notched, oval, sickle-shaped, circular, teardrop, blunt, heart-shaped, arrow-headed, and more. Some climb while others descend, some mound or bloom daintily, others sprout or cantilever. Knowing the habit of each, he draws a multicelled planting map that looks like swirling fingerprints or a paint-by-number guide, with each segment a plant species referred to by Latin name.

  “They begin like paintings,” he explains. “Then they develop texture and depth.”

  As a science-based art form, it’s a fusion inspired by many muses. The plants are drawn on flat paper, so each design does indeed begin like a painting. Then the artwork morphs into a sensuous sculpture of touchable, biological, prunable shapes and colors. Leaves, flowers, stems dance in the air, a slow-motion ballet. He may try to choreograph them to some degree, but the ensemble will succumb to wild swings of improvisation, depending on the weather. As frogs, birds, and insects take up residence, they’ll add a croaking-chirping-buzzing chorale, with some notes foreseeable and the rest jazz variations.

  Although the plants naturally curve, clear lines and clean edges give the finished work a tone of sensuous elegance, not disarray. It’s lofty and complex, not cluttered. The plants aren’t exactly wild, but they can flourish in unique ways. In that sense, it’s more like chaos aligned—a deliberate, contained, carefully measured, masterfully executed free-for-all.

  Practical botany, hydraulics, physics, and materials science are essential scaffolding for the artistry. Thousands of individual plants are inserted by hand into pockets on a flat felt sheet that’s rigidly framed and will be watered and fed, rain-style, by intermittent showers from a hidden pipe running across the top. Despite the lack of soil, the plants quickly flourish, covering the felt and pipe. The overall effect is a gulp of wild nature that hits you in the solar plexus. This is a garden you stand up and greet at eye level, as you would a person. It invites you to touch and smell it. Look up, and it looms four stories above you like an expansive forest understory, not a fairy-tale giant. Close in, it creates its own weather bubble and is quite shady and moist if you stand beside it and tilt up your chin at the dizzying vegetation. Balancing on a very thin wire between tame and free-willed, it seems both intimate and indomitable.

  VERTICAL GARDENS, LIVING roofs, and urban farms are going mainstream everywhere. A few of my favorites: Mexico City’s towering arches carpeted in fifty thousand plants astride car-clogged avenues; the blooming brocade of native plants adorning the inner walls of the Dolce Vita shopping center in Lisbon; the glassed-in courtyard of Milan’s Café Trussardi, where a canopy of frizzy greens and purples floats above diners and cocktail-sipping flaneurs, trailing vines and flowers like a hint of heaven; the golden wheatfield atop the Canadian War Museum in Ottawa; nine sinuous houses buried under earth and grass in Dietikon, Switzerland; the Grange, atop two buildings in the Brooklyn Navy Yard, where you’re surrounded by organic vegetables and views of the Hudson. The roof of the Chicago Botanic Gardens’ Rice Plant Conservation Science Center doubles as a garden visited by millions of people and a botanical laboratory, and the roof of Chicago’s City Hall also serves as a study site, with the usual black tar on one side and a wildflower garden on the other. (On summer days, the ambient air above the planted side measures as much as 78°F cooler than the air over the old blacktop.) And living rooftops are becoming hot property. One U.S. company has already sold 1.2 million square feet of sprouting, blooming, bird-, bee-, and butterfly-enticing roofs, mainly to private residences.

  Other living roofs and vertical garden companies have sprung up and begun greening all sorts of buildings, from hospitals, homes, and police stations to banks and offices. Some use hydroponic methods; others plant in turf on the roof à la the European tradition. A former Renault factory in Boulogne, France, has been reborn as a school with an undulating green-roof that reduces heating and cooling costs. The design firm Green over Grey, based in Vancouver, British Columbia, has created some spectacular living walls for sites in Canada, including the international building at Edmonton Airport, where arriving visitors inhale a shot of oxygen and plant-scrubbed fresh air from a gigantic living wall whose design swirls were inspired by high-altitude cloud formations. “Jungle Waterfall,” their dramatic, multistory cascade in an office building in Vancouver, includes tropical trees, and a maintenance crew occasionally has to harvest the pineapples lest they fall and hit passersby.

  Planted walls and roofs and sustainably designed buildings, along with wildlife corridors, city parks, solar and wind power, and trees aglow with bioluminescent foliage (to replace streetlamps), are but a few of the initiatives gaining popularity in the U.K., Germany, Taiwan, the United States, and many other places worldwide. Roofs planted with sedums and succulents blossom, changing color with the seasons, while being low-maintenance, reflecting heat, and providing a habitat for birds. The goal is homes and public spaces that are living organisms that will scrub the air of pollutants, increase oxygen, reduce noise, save energy, refresh the spirit, and sink our roots deeper into the natural world.

  IN CONTRAST TO Blanc’s elegantly formal walls for the Quai Branly and a similar project at the Athenaeum Hotel in London, his own house on the outskirts of Paris is a throbbing green Mardi Gras of microhabitats, with knolls of lance-shaped leaves, jutting rocks, prongs of tiny flowers, thick heart-shaped leaves, arrow-leafed philodendrons with roots adrift in a flowing stream. You don’t so much enter the abode he shares with his longtime partner, the actor Pascal Henri (a.k.a. “Pascal of Bollywood”), as join a green rhapsody, or possibly a green bedlam, and become part of the cascading carnival of fronds, mounds of moss, umbrellaing ferns, twig elbows, searching roots, and leafy limbs probing at everything, including you. The superabundance of leaves caresses you lightly with barely discernible veined fingers as you pass. Beaded curtains serve as doors, and free-flying coral-beaked waxbills wing from room to room. Bouncing frogs and slithering lizards roam the house at ease, eyes rotating, tongues occasionally unfurling like party favors. At a Magritte-like Surrealist window, a bushy shrub on the inside echoes its twin on the outside. Your eye shimmies. Inside, outside—who can say where they begin or end? Glass is only liquid sand, after all, and only ever in motion, hourglasslike, pouring so slowly that our eyes read it as solid.

  Blanc’s study is a green thought in a green shade where he’s walking on water. Literally. The floor is a sheet of plate glass atop a 20' x 23' aquarium, home to a lush expanse of vegetation and over a thousand tropical fish. Holding 5,283 gallons of water, it’s loaded with plants whose long white roots ripple like medusas, as they naturally purify the water and also provide grottos for the fish.

  The large wall behind his glasswork table is a weave of plants with plush textures, mossy tussocks, cascading fronds, and a kaleidoscope of greens. At the base of the living walls, a narrow stream flows, providing nourishment for roots and refreshment and nesting sites for the birds. He dips a hand in as a bird glides overhead to perch in the rhododendrons. Here and there, algae, moss, and liverworts have sprung up on their own. In a large bookcase, nearly all the books have green jackets. Only little brown bats and bombardier beetles are missing.

  “I take my shower outside every day, even if it’s snowing,” he confesses. “I refu
se to heed the limits between inside and outside imposed on a human lifestyle that migrated from tropical origins to colder, even glacial climates. To heighten the absurdity, life in tropical cities requires air-conditioning to cool the indoor atmosphere. Wherever one goes in the world, regardless of the season, it is necessary to either heat or cool dwellings.” This merits a hand lifted to the absurdity. “We need buildings with a better thermal balance.”

  Despite his serious purpose, a spell of playfulness pervades his preferred habitat, as it does his person. His shirts all seem to be patterned in leaf designs; he wears green shoes, has a two-inch-long thumbnail painted forest green, and wears a streak of bright green in his hair. For a moment I think he might have a single leaf of Iris japonica growing from his skull—his green forelock is shaped like one of its long, tapering leaves. It is his signature plant: one often sees Iris japonica dangling down forest edges in the wild. Blanc uses it in most of his installations as an echo of gently cascading water.

  “We live in an era where human activity is overwhelming,” he continues. His chilled white wine, Vogue menthol cigarette, computer, and electric lights make it clear that he does appreciate cosmopolitan life. In fact, he’s spent all of his life living in cities—while making forays to some of the wildest places on Earth.

  “I think we can reconcile nature and man to a much greater degree.”

  He’s not alone in that conviction. A good start may be rethinking our houses, because at the racing heart of every city is still the ancient, unalienable idea of home.