“Try some,” he says, offering me course two.

  I taste a piece of kelp curl, which is chewy and rather tasteless, more texture than flavor, but perfect for noodling with sesame oil or in miso soup, as I’ve often eaten it in Japanese restaurants. Bren sells oysters and kelp to local residents and restaurants and to chefs in Manhattan.

  “I think of this actually as ‘climate farming,’ ” Bren says, “because the kelp soaks up huge amounts of carbon and can easily be turned into biofuel or organic fertilizer. So I’m in conversation with companies, NGOs, and researchers right now. Kelp is over 50 percent sugar. The Department of Energy did a study that showed if you took an area half the size of Maine and just grew kelp, you could produce enough biofuel to replace oil in the U.S. That’s stunning! And without the negatives of growing land-based biofuel, which by the way is actually terrible. It wastes a lot of water, fertilizer, and energy. But here you can have a closed-energy farm, using zero fresh water, zero fertilizer, and zero air, while providing fuel for local communities. I grow this kelp here for food, but you could plant it in the Bronx River or in front of sewage treatment plants, which would reduce their polluting. Or you could grow kelp for biofuels.

  “Over the past ten years I’ve been struggling with all of these things and trying to figure out how they could come together. Think about it. Growing food in the ocean: no fertilizer, no air, no soil, no water. None of these things that are hugely energy-intensive and huge climate risks to both freshwater and soil. When you put all of this together it’s so exciting. It’s so exciting! I can almost smell the possibility of a blue revolution joining the green revolution. And because it’s vertical farming, it will have a very small footprint.”

  Not everyone agrees with his methods, especially old-style environmentalists, which he’s the first to point out.

  “Now there’s a real pushback, of course, from some conservationists, because people think of the oceans as these beautiful wild spaces—which I’m so sympathetic to because I’ve spent my life on the ocean. But we’re facing a brutal new reality,” he says, his face aflame with resolve. “If we ignore the greatest environmental crisis of our generation, our wild oceans will be dead oceans. Ironically, climate change may force us to develop our seas in order to save them. We need to do that and also reserve large swaths of the oceans as marine conservation parks. This won’t solve every problem we’re facing, but it will begin to help.”

  Behind all of Bren’s enthusiasm is a wave of widely shared concern about how climate change is acidifying the seas. He’s part of a transitional generation that feels the urgency of reconciling their lifestyle with the planet’s health. Call it what you will, pioneering or bioneering, because of his commitment, he was invited to join the Young Climate Leaders Network, which supports a small group of “innovative leaders and visionaries, including many who operate largely outside of the traditional environmental community, working for climate solutions.”

  Bren’s eyes rest on the water. “There’s no doubt, this will mean reimagining the oceans, which is heart-wrenching and controversial for a lot of people who revere the oceans as some of the last wild places on Earth, places untouched by human hands.”

  Yet the truth is that oceans are not untouched by human hands. In 2007, owners of the only salmon farm in Ireland woke one day to find its hundred thousand salmon devoured by a horde of jellyfish. Throughout the world’s oceans, trillions of umbrella, parachute, and bell-shaped jellyfish have been swarming, lured by rising temperatures, nutrient-rich agricultural runoff, and pollution. With semitransparent stealth, they sneak up on flounder, salmon, and other large fish favored by human fishermen and colonize a slew of habitats, where they eat or oust the local fish. Oceana Europe, which works to restore and protect the world’s oceans, attributes the soaring number of jellyfish to climate change and the human overfishing of tuna, swordfish, and other natural predators. City-dwellers are combating blooms of jellyfish in Tokyo, Sydney, Miami, and other harbors. During one recent summer, record numbers invaded the shallows of South Florida and the Gulf of Mexico. In Georgia, on one Saturday alone, Tybee Island Ocean Rescue reported two thousand serious stings.

  The sea is a spirit level, a pantry, a playground, a mansion rowdy with life, a majestic reminder of our origins, another kind of body (a body of water), and female because of her monthly tides. But her bones are growing brittle, her brine turning ever more acidic from all the CO2 we’ve slathered into the air and all the fertilizer runoff from our fields. While that’s terrible for creatures like coral, oysters, mussels, and clams, whose calcium shells can soften and dissolve, the warmth is a tonic for starfish, which are roaming farther north in throngs. Until, that is, their shellfish prey vanish.

  “Environmentalists have been asking the wrong question,” Bren says after a moment. “It’s not just about: How can we save the oceans? How can we protect the sea animals? I agree, all of that’s important. But we also need to flip our way of thinking and ask: How can the oceans save us? How can it provide food, jobs, safety, and a sustainable way of life? I’m convinced the answer is ocean conservation with symbiotic green farms.”

  Last thing, we check the remaining crop of mussels, which means back-straining, heave-hauling them up from the depths where they’re filling their mesh socks nicely, growing through the lattices like shiny black buttons, still too small for harvesting. So back they descend, too young for saffron cream sauce. I can see why he finds this part of his workday like checking on a nursery.

  Scanning the lapping ripples of the Sound, it doesn’t look like an industrial landscape at all. And yet the amount of food growing below the water is incredible. There are two tons of kelp on Bren’s longlines alone. I like Bren’s “symbiotic” way of thinking. We billions of creative, problem-solving humans don’t have to be parasites in our environment—we have the technology, the understanding, and the desire to become ecologically sustaining symbionts.

  On our return to Stony Creek harbor, we again pass the island-perched village of Victorian mansions and salt-white cottages, with stone chimneys for burning up yesterday’s disappointments, rain-rattled windows, sea-spying porches, and wind-worn trees and gardens. And always the deep and dazzling blue of the Sound, with hidden reefs and ledges, devious currents corkscrewing just below the surface, and, during storms, waves running like greyhounds.

  The new dock looks trim, clean, and stubbornly well anchored against hurricanes. A pair of black cormorants perches on a rocky knob, and Bren gestures a welcome. Superstition tells of drowned fishermen returning as hungry cormorants, dressed in black rain gear, with webbed feet instead of boots.

  Despite the cold breeze there’s a warm afternoon sun. Soon the tide will be walking in and the pink-legged seagulls skimming the shoreline. In a few months the summer crowds will arrive to eat fresh seafood, attend the puppet theater, fall asleep to the slurred voice of the ocean, and enjoy the ecstasy of coastal life and clean water, with time strapped to their wrists.

  PART II

  IN THE HOUSE

  OF STONE

  AND LIGHT

  ASPHALT JUNGLES

  Watching Budi tumbling and climbing, at play with ball and shadow and iPad alike, I marvel at the road the human race has traveled. Open your imagination to how we began—as semiupright apes who spent some of their time in trees; next as ragtag bands of nomadic hunter-gatherers; then as purposeful custodians of favorite grains, chosen with mind-bending slowness, over thousands of years; and in time as intrepid farmers and clearers of forests with fixed roofs over our heads and a more reliable food supply; afterward as builders of villages and towns dwarfed by furrowed, well-tilled farmlands; then as makers, fed by such inventions as the steam engine (a lavish power source unlike horses, oxen, or water power, and not subject to health or weather, not limited by location); later as industry’s operators, drudges and tycoons who moved closer to the factories that arose in honeycombed cities beside endless fields of staple crops (like corn, wheat, a
nd rice) and giant herds of key species (mainly cows, sheep, or pigs); and finally as builders of big buzzing metropolises, ringed by suburbs on whose fringes lay shrinking farms and forests; and then, as if magnetized by a fierce urge to coalesce, fleeing en masse into those mountainous hope-scented cities. There, like splattered balls of mercury whose droplets have begun flowing back together, we’re finally merging into a handful of colossal, metal-clad spheres of civilization.

  Among the many shocks and wonders of the Anthropocene, this is bound to rank high: the largest mass migration the planet has ever seen. In only the past hundred years, we’ve become an urban species. Today, more than half of humanity, 3.5 billion people, cluster in cities, and scientists predict that by 2050 our cities will enthrall 70 percent of the world’s citizens. The trend is undeniable as the moon, unstoppable as an avalanche.

  Between 2005 and 2013, China’s urban population skyrocketed from 13 percent to 40 percent, with most people moving from very rural locales to huddled megacities whose streets jingle with chance and temptation. At that pace, by 2030, over half of China’s citizens will live in cities, and instead of farming food locally they’ll import much of it from other nations, paying with the fruits of industry, invention, and manufacturing. That’s already the case in the U.K., where by 1950 a checkerboard of cities embraced 79 percent of the population. By 2030, when the U.K.’s city-dwellers reach 92 percent, it will be a truly urban nation, joining a zodiac of others. Ninety percent of Argentinians already dwell in cities, 88 percent of Germans, 78 percent of the French, 80 percent of South Koreans. For a rural nation, one needs to journey to Bhutan, Uganda, or Papua New Guinea, where nearly everyone lives in the countryside, with a scant 10 percent committed to metropolitan life—so far.

  Our city-chase has reached such a frenzy that the idea of migration doesn’t begin to capture its rush or rarity. This isn’t surprising in an economically lopsided world where, too often, newcomers end up in crowded shantytowns, favelas, and slums, because cities concentrate the very poverty from which they offer an escape. But that won’t slow the influx as long as hope wears Nikes and is steeped in fumes.

  Oz-like cities shimmer as beacons of prosperity, with enhanced education, better medicine, more jobs for women, and wide streaks of upward mobility. Even environmentally, cities can eclipse sparsely settled country life. When roads, power lines, and sewers lie closer together, they require fewer resources. Apartments are insulated by the civil geometry of the buildings, making them easier to heat, cool, and light. Crowded neighbors can share public transportation, and most destinations tend to be close, within walking or biking distance; people rarely need cars. As a result, city-dwellers actually create a much smaller carbon footprint than rural-dwellers do. Cities like New York boast the lowest amount of energy use per household and per person, and so, paradoxically, although the city as a whole uses more energy, each person uses less. It seems counterintuitive, but city life can be a more eco-friendly way for humans to live. Cities in developing countries also use less energy—but that’s because the number of poor tends to be higher there and they consume less, including less food and fresh water.

  Still, despite clustering services and leaving smaller individual footprints, the record number of people fleeing the countryside for city life is worrisome to climatologists, because cities are environmental game-changers. Big cities are hotspots, on average ten degrees warmer than their surroundings, and they emit most of the planet’s pollution, as cars prowl their streets and food caravans travel long distances to stock their groceries. On some summer days, the air hangs thickly visible, like the combined exhalations of millions of souls. Steam rising from vents underground makes you wonder if there isn’t one giant sweat gland lodged beneath the city.

  One of the paradoxes of our age is that we’re urban primates who are still adapted to the wilderness, which we long for and need, at the same time that we’re destroying, building over, and farming all that’s wild. Since the crowd-rush to these asphalt jungles is accelerating, we need ingenious ways of harmonizing city life with human and planetary well-being. Our challenge will be finding a way to have both, while also preserving the planet.

  Some of the best ideas I’ve encountered do just that, transforming our cities from grimy energy guzzlers into dynamic ecosystems.

  City parks are essential, but in addition, picture shade-loving wildflowers in gated alleyways, fresh vegetables growing on roofs and piers, lushly planted walls, vertical farms in skyscrapers, rooftop beehives brewing honey, and nature trails threading through rusty old infrastructure. Greening a city with vegetation is a proven way to cool it down, filter the air, suck out carbon dioxide, ladle in more oxygen, and offer pockets of calm amid the bustle and din.

  Hoping to achieve that intermingling, a new branch of environmentalism known as “Reconciliation Ecology” has emerged, which strives to preserve biodiversity on our doorstep in cities and other human-dominated habitats. The term “reconciliation ecology” was coined by Michael Rosenzweig in his book Win-Win Ecology, and it has a lovely ring to it. It suggests fence-mending and coexisting in harmony, not a wallop of blame. It’s based on figures showing that we haven’t enough unsettled land left on Earth to protect all of life’s biodiversity, but we can make room for plenty more in our cities and yards.

  Along country roads near my house, where cornfields and houses predominate, you’ll see nest boxes for bluebirds, provided by thoughtful bird-lovers because natural tree cavities have grown scarce. When replacing wooden fence posts with steel ones led to the rapid disappearance of shrikes (medium-sized birds with hooked beaks like birds of prey), locals restored the wooden fence posts (on which shrikes like to perch), and the shrikes returned. These may be small acts of reconciliation, but if you create enough of them it can change the big picture. And not just in the countryside. Some of the most improbable-sounding efforts are blurring the line between civilized and wild. “Wastewater Treatment Plant” may not sound like a natural or particularly scenic destination. But some symbiotically minded towns have been designing a new breed of wildlife preserve, one that gives recycling a lively twist. Instead of dumping treated water, they return it to nature as the essence of an ecosystem that offers food and habitat to animals. As the water is further purified by vegetation, migrating and native birds find a home, entangled communities of plants and insects take up residence, and a hodgepodge of wild animals bustle in.

  City-dwellers then needn’t travel far for an interlude to refresh their habit-dulled senses. Strolling, gawking, sitting, camera-clicking, humans become one more changing feature in the perpetual tableau, another flock of familiar creatures to whom the scores of nesting birds pay little mind.

  A favorite such preserve of mine is the Wakodahatchee Wetlands in suburban Delray Beach, Florida. On a boardwalk raised ten feet above any hazard, one can watch an alligator gliding among the bulrushes, fish defending their mud nests from marauding turtles, dabbling ducks and teals, wading birds stalking their prey. The shallow water and raised trail make many dramas visible from above, including whiskered otters catching whiskered sail-finned catfish. Pig frogs grunt like their namesakes. If you’re lucky, you might see a patch of water fizzing like frying diamonds in the sun—where a male gator is bellowing in a bass too low for human ears. Or you might spot a giant prehistoric apparition standing like a sentinel in the water, as an endangered wood stork displays its distinctive gnarled-wood bald head and long curved beak.

  The wooden walkway loops for nearly a mile through fifty acres of swamps, marshes, ponds, reeds, and bogs. Wherever water and land meet, life seems to thrive. Flapping around an archipelago of brushy and treed islands, ibis run a regular feeding patrol to nests full of squawking chicks.

  Despite the usual urban hubbub, 140 species of birds broadcast on every channel at Wakodahatchee, from a pitying of collared doves to a pandemonium of monk parakeets. Red-nosed moorhens create a steady background score of trumpeting, clucking, and loud monkey-cackling
. Courting roseate spoonbills play the castanets of their bills. Red-winged blackbirds spout the only buzzwords.

  Though surrounded by restaurants, offices, condos, malls, and highways, Wakodahatchee’s wetlands attract a bounty of life, including wild plants one rarely sees in cities. What at first seems a flush of algae, or a pointillist canvas of sunstruck water, is brilliant chartreuse duckweed. This simple aquatic plant floats everywhere on the slower-moving waters of our planet, offering food to birds, shade to frogs and fish, and a warm blanket to alligators and small fry. One day it may also provide a cheap source of high protein for humans (it’s already eaten as a vegetable in some parts of Asia) or a cheap producer of biofuel that will power cars while filtering carbon dioxide from the air.

  There’s no stigma attached to reconciliation projects being lucrative. Israel’s Red Sea Star Restaurant, for example, 230 feet off the shore of Eilat, is a combination bistro and observatory, seating people in its colorful, marine-inspired dining room sixteen feet down from the surface on the sandy sea floor. Plexiglas windows offer diners, sitting on squid-shaped chairs under dimmed, anemone-shaped lights, a view of a wealth of sea creatures in the coral gardens by day or night. Equally curious fish also get to ogle the diners. It happens to be an architectural showpiece, but it’s also an ecological triumph that has restored a coral reef that was lost through human pollution and overuse. Architects began by choosing a barren stretch of sea floor, laying down an iron meshwork, and transplanting coral colonies onto the trellis, where they cling like slow-motion trapeze artists and continue to attract marine life.