Informal trash collectors may gain "green" jobs in the formal sector with the closure of the world's largest trash dump. Photo: basmati - authentic help (flickr)

Does your old lunch bag go in the garbage or the recycle bin? For hundreds of thousands of garbage scavengers worldwide who make a meager living by collecting, recycling and reselling trash, that decision is worth its weight in cash.

But at the end of this month, the world’s largest dump will close, leaving many scavengers without a livelihood.

The closure of Mexico City’s Bordo Poniente dump, which will divert nearly 12,600 tons of garbage into recycling and composting plants daily, reports the Associated Press, is a win for environmental groups. It’s also a win for the city’s mayor, Marcelo Ebrard, who announced the closure will take place December 31, the day before he steps down to focus on his campaign for the 2012 presidential race, the LA Times reports.

But trucking the garbage directly to sorting plants leaves out a key player in the waste management system—dump dwellers who for decades have sorted much of the trash and sold the recyclables for income, like freelance garbage collectors.

If the city agrees as promised to negotiate with the guild that the garbage scavengers have organized to voice their concerns, it could mean formal jobs for pepenadores, jobs that pay many times more than what they earn now reselling what they find. After all, living on the dump creates a level of trash expertise and relying on it for an income is quite an incentive to sort it efficiently. They’ve been greasing the wheels of the old system for years; it seems only fair they be part of the new one.

Washington, D.C.’s bike sharing program has 1,100 bikes. London’s system has 6,000. And Paris has more than 20,000.

But on the other side of the globe, Hangzhou, China has them beat with more than 60,000, according to a recent report by National Geographic.

To see how it all works, check out this short from Streetfilms:

Bike shares -- where a user can pick up a bicycle at one service point, ride it, and then drop it off at another and walk away -- are growing in popularity. China, along with many other developing nations, has a long-held cultural tie to bicycling. Demand for automobiles skyrocketed in recent decades, but in a city of 6.7 million like Hangzhou, it would be impossible to build enough roads to support this, not to mention environmental concerns.

Bike shares are cheap (nearly free for many in Hangzhou), highly accessible, and part of a sustainable urban growth model. Hangzhou hopes to expand its system to 120,000 bikes by 2020 and other cities are taking notice of its success. Companies in Beijing, Rio de Janeiro, and Mexico City are making a go of it and hope to remove the training wheels soon.