How last year's Christmas trees are rebuilding New Orleans' coast

Colombia’s National Development Plan for cattle ranching seeks to reduce pasture land from 94 million acres to 70 million acres while increasing cattle numbers from 23 million head to 40 million. The program focuses on planting trees on grazing land and the "cut and carry method," whereby farmers grow fields of shrubs and distribute the fresh cuttings to cows in pastures. The result is greater cattle productivity and a more eco-friendly farming system.

In order to encourage people to properly dispose of their waste, New Delhi Municipal Council (NDMC) has installed smart vending machines for recyclable waste at Connaught Place and India Gate. In return for making the sustainable waste choice, users receive monetary rewards via e-wallet.

During the Industrial Revolution, farmers began harvesting monoculture crops which produced promising profits but proved harmful to the soil and weakened the immune capabilities of native plants. Lately, however, permaculture practices have been on the rise amongst farmers to better diversify their yields and reduce reliance on chemicals.

Scalesia, is a species of tree native to the Galapagos Islands that is quickly disappearing thanks to human activity. With much of the island's wildlife dependent on this tree, the ecosystem is threatened with the tree's extinction. Conservationists have taken action, however, by planting thousands of the trees as part of a shade-grown coffee operation.

What do you get when you combine the efforts of an engineering company with an energy company? In the Netherlands, you get a new type of environmentally sustainable roads. PlasticRoads, a piloted initiative in the city of Zwolle, uses discarded plastic to build bike paths that help cut down on plastic waste.

Across the country, projects that mine landfills for reusable metals and soils are underway. Can such mining prove profitable enough to spur similar efforts on a grand scale? So far, some projects have seen profits while others have not. But as society increasingly values pollution and greenhouse gas reduction, incentives for refuse mining can only grow.

In Eskilstuna, Sweden, there is a different kind of shopping mall – one that sells used and upcycled goods. In an effort to combat consumerism and bolster sustainability, the mall, called ReTuna, is nicely curated and organized, making second-hand shopping mainstream. The mall sees 700 people each day, on average, and has sold nearly $3.5 million worth of items.

Lamakani, a small village in India, went barren and townspeople completely depended on water tankers after a drought in the 90s. One leader initiated a watershed movement. They applied a series of approaches which included things like watershed development, bans on grass grazing and tree falling, and collaborating with local artists to communicate messages of conservation. Now, the town is lush again.

After years of drought and land-clearing that left Niger with few trees left, the country now boasts about 200 million trees, which have mostly been reestablished naturally. While the effects of climate change could threaten the future of these trees, this method has also increased crop yields in villages. This model of letting trees grow back with little human influence could be implemented in other countries.

In Kenya, like other countries in the world, deforestation is the major driver of tree cover loss. To solve this, a local startup called Seedball Kenya has developed the seedball technology whereby seeds of indigenous tree and grass species are coated with charcoal waste mixed with nutritious binders then thrown like balls into the planting grounds.