Mantu Kar, 45, works at a compost-making plant in Uttarpara, near Kolkata. Subrata Biswas/AP

The top cities mass-produce compost, use landfill gas to heat a stadium, and “deconstruct” rather than demolish homes.

What can you do with an old landfill that’s seeping plumes of climate-baking methane? In Seoul’s case, engineers tapped into the garbage and used its gas to heat offices, homes, and even its World Cup Stadium.

That innovative answer to an environmental problem helped earn Seoul a place among 10 others to win the 2016 C40 Cities Awards at the C40 climate conference in Mexico City. Climate experts and former mayors selected the cities for having sustainability projects that reduce emissions, bolster resiliency, and promote social equity. Now in its third year, the awards give these burgs much-deserved publicity, but no cash (though their efforts provide their own rewards in building the green economy and reducing damages from flooding.)

Here are some of the cities honored at the C40 conference; winners not pictured are Shenzhen, Melbourne, and Curitiba, Brazil.


Greg Wahl-Stephens/AP

Portland, Oregon, is one U.S. city that will continue the climate fight despite probable lack of support from the Trump administration. Its ambitious climate-action plan, a descendant of the first-such plan in the U.S., aims to cut carbon emissions 80 percent by 2050 by promoting green jobs, nurturing biodiversity corridors and the urban canopy, and getting people out of gas-powered cars and into electric vehicles, public transit, and onto bikes. Above, Portland’s Angela Ramseyer stands outside an old home she is “deconstructing.” An alternative to traditional demolition, deconstruction lets workers salvage and reuse quality building materials. This fall, Portland became the first U.S. city to require deconstruction for its oldest homes.


Lee Jae-Won/AP

Haneul Park in Seoul, pictured here, used to be a dump stuffed with 140 million tons of trash. As the garbage rotted, it leaked methane, which the city decided to retrieve with extraction wells stuck into former landfill. Fans blow the gas into the wells and then into pipes running through the neighborhood, where it’s used to provide heat to offices, houses, and the Seoul World Cup Stadium. Aside from exploiting trash, the city is using LEDs for home lighting, installing scores of solar panels, and building cool roofs for maximized energy efficiency.


Tomohiro Ohsumi/AP

Yokohama also hopes to cut emissions by 80 percent by mid-century, and a big part of that plan relies on its Smart City Project. Initially created to spread Japan’s energy technology to other countries, the project uses solar panels and a smart grid to slice energy usage in homes and businesses by as much as 22 percent. Above, a worker strolls past digestion tanks in Yokohama that decompose sewer sludge.


Jens Dige/AP

Extreme precipitation is expected to deliver huge impacts in a warmer world. Copenhagen, already dealing with billions of dollars in rain-related disasters,  is preparing by beefing up its flood defenses. The so-called Copenhagen Cloudburst Management plan has a priority of steering floodwaters away from residential areas and transit systems. It relies on a sprawling network of drains that channel rain into buried basins and canals, and also gives incentives for homeowners to disconnect rainwater pipes from the sewer system, to lessen flooding.


Subrata Biswas/AP

There’s a whole lot of organic waste in Kolkata, but rather than let it just sit there, the city is encouraging people to compost it. Local communities produce as much as 27 tons of rich compost and sell it for about $1,000 each day. Kolkata expects its sustainability efforts to benefit more than a million people, including pickers who go around the streets sorting biodegradable garbage from other kinds of waste. Above, a worker mans the compost-making machine at a solid-waste facility just outside of town.


Thibault Camus/AP

Paris is preparing to endure the ravages of climate change with an adaptation plan chasing more than two-dozen objectives. It addresses heat waves—which are expected to soon become longer and deadlier—with actions like converting public fountains into “paddling pools” and keeping parks open 24 hours a day, so people can get respite from the urban-heat island. For health problems related to a warmer climate, it’s cracking down on the most-polluting vehicles, doing more air-quality monitoring, and prepping for possible outbreaks of mosquito-borne diseases like malaria and chikungunya. The city also plans to plant 20,000 new trees. Above, a woman tends to a garden on the roof of Henri Matisse college.

Addis Ababa

Mulugeta Ayene/AP

Last year Addis Ababa became the first place in Sub-Saharan Africa to deploy a light-rail transit system, and it has become wildly popular, with roughly 60,000 people riding each hour. The system cuts the city’s emissions as well as gives a welcome lift to the 60 percent of the population that otherwise would be walking. Above, a woman holds her baby in a shawl while taking the Addis Ababa LRT.



Sydney is stretching the energy efficiency of buildings with its CitySwitch Green Office program, which to date covers some 34 million square feet of business space. The program encourages offices to be more sustainable by better managing waste and switching to on-site renewable energy and more-efficient lighting. Sydney and other cities participating in the national program are expected to cut 55,000 tons of emissions each year, as well as save more than $10 million in energy costs.

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