20 years later, a small Maine town finally found a way to solve its 27,000-ton carpet dump problem

Phone lines in Africa and South Asia would never have gotten to the poor - but these places have leapfrogged over last-century technology and gone straight to mobile phones. Now the same thing is happening with off-grid solar power: the fastest -- perhaps the only – way to power the poor.

Nationally, only about a third of municipal solid waste is recycled. An initiative to use simpler, standardized signs and labels is helping communities reap greater benefits from recycling.

Citizens in Cairo have been working to make the streets cleaner in an effort to create more pride for the country and get the government's attention. From picking up trash and painting lampposts to collecting donations from passersby, the community is working together to make a new Egypt.

Lack of access to sanitary bathrooms in the village of Kivalina, Alaska led to the implementation of a novel, home-based water sanitation system, currently being tested for effectiveness. The hope is that it proves to be a solution for areas all over the state with lack of access to clean water systems.

A Dallas urban neighborhood was dilapidated with abandoned storefronts and offered no vitality for pedestrians. A group of artists and community members created Build a Better Block, in which local artisans and small businesses took over a vacant block and transformed it for a limited time to encourage the ingredients for more permanent urban renewal.

Alleys in Seattle were once places of illicit, illegal, and unsanitary activity. The International Sustainability Institute in Seattle began organizing music and art events to bring in people, which, in turn, cleaned-up the crime and garbage. As an urban development strategy, adjacent vacant storefronts re-opened for business and beautification could be seen in new gardens.

Although residents turn up their air conditioners, Louisville heat is increasing the city’s death rate by 39 people every year. The city mayor launched a tree commission for planting more trees and since 2011 has planted over 12,000 trees. The canopies from the tree offer cooling shade and bring down the temperature of the city as a whole. The response also includes the installation of green roofs and in-depth research on urban heat islands.

The Oak Cliff neighborhood in Dallas suffered from recession-closed businesses and crime. Then community members used placemaking, in which people shaped their own environment to improve the quality of life, and the concept of Build a Better Block, which was a pop-up event showcasing art, food, music, and local faire. The idea gives citizens a fresh look at the possibilities through which to transform the space in which they live, and it has attracted attention across the country and around the world.

Throughout India, wastepickers – people who scour landfills for garbage they can sell to recyclers – live at the bottom of society. But the city of Pune did something radical: with the help of a collective, they did away with expensive garbage trucks, and now all household garbage is collected by wastepickers with pushcarts. Pune saves millions of dollars each year and recycles more – and the wastepickers have decent wages and social standing. The concept is now spreading globally.

In Fayetteville, the Mayor and Police Chief have taken a personalized approach in seeking a solution for blighted, low-income neighborhoods and are working to increase the number of city staff on-hand to help address issues like decrepit buildings, as well as decrease the disparity in resources allocated to maintaining these neighborhoods. But many challenges remain, and the line between the government's role versus the private homeowner's responsibility remains difficult to define.