There are few places where locals rely on the Earth more than the farmers in the foothills of the Himalayas. Their homes are constructed with tightly packed dirt; they spend their days tilling the land and use wood from nearby forests to light and heat their homes. Their diet revolves around food cooked on those wood-burning stoves.
But they are not the only ones so reliant on the wood. The forests that border the farmland are also home to some of the world's most beautiful, and ferocious, animals. Wild tigers, rhino and elephants, snakes, birds and other species frequent the area.
The task of gathering wood falls to the women, who spend three or four hours a day in the forests. There, they risk run-ins with their roaming neighbors. At the same time, the loss of habitat threatens these endangered species, destroys local fauna, and has detrimental effects on the air and soil quality.
"We are talking about an area of in Nepal which borders India. It is one of the most densely populated areas and one of the most productive," Shubash Lohani tells CBS News. Lohani is the deputy director of the WWF's Eastern Himalayas Program. "It is also teeming with wildlife. So it is important from the biodiversity and the economic perspective."
In an attempt to create a safer environment for both the farmers and the indigenous species, the WWF is working with the local government to help the region's 8 million residents convert from wood-burning stoves to biogas stoves.
Biogas units feature simple cement-lined pits, called digesters, where a combination of water, cow dung and human excrement are safely mixed together by turning a crank above the pit. As the mixture decomposes, it creates clear, odorless methane gas. This would happen during natural decomposition -- but for the stoves, the gas is piped into the house and used as fuel. This saves methane from freely escaping into the atmosphere.
Through a small pipe connected to the cement-lined pit, the methane makes its way into the indoor stove. There, it lights a bright blue flame.
"The methane gas produced as part of the natural process is captured and burned to produce energy, carbon dioxide and water," explained Lohani. "Carbon dioxide is less harmful than the methane. Therefore biogas in fact is helping with the reduction of methane gas emission into the atmosphere by breaking it down to carbon dioxide and in the process providing energy to the local farmer to cook their food."
"If methane were to hit the atmosphere as gas, it's more than 20 times worse than CO2 hitting the atmosphere," added fellow WWF researcher Keya Chatterjee in an email. It is also reducing carbon dioxide emissions because the biogas stoves produce less CO2 than wood-burning stoves.
At $548 each, the stoves are a hefty investment for the farmers. WWF is subsidizing 25 percent of the cost, as well as installing functioning toilets in the traditional mud huts common in the villages. The toilets further decrease the villagers' need to enter the forest -- in homes without toilets, the villagers typically head to the woods to defecate. The most common time to head to the woods is dawn and dusk, which is also prime time for the animals to be active and walking around. It's also harder to spot poisonous snakes once the sun goes down.
Now in phase two, the partnership has led to the installation of more than 8,000 biogas stoves. They hope to reach 40,000 before the project is complete. There are similar programs around the world. The non-profit Heifer International provides biogas stoves to families in South America. The Agricultural Development and Training Society works with 1,165 villages in India,
The WWF project is part of the Power the World initiative, which seeks to bring sustainable energy solutions to one million people. It was designed to help farmers, but Lohani says its starting to reach a group he never expected.
On a 2011 trip, he met a rickshaw driver who wanted to install a biogas stove. The program requires all recipients to own at least two cattle, so that they have access to the necessary cattle dung.
This driver did not own any cattle, but he was so excited about biogas that he devised an entrepreneurial plan: they would install a working toilet in their home, and invite all of their neighbors to use the toilet at any time. His wife would also collect cow dung from the side of the road. Lohani was so impressed that he worked with the local village chairman to help the man install a biogas stove.
The 7,500 stoves installed during phase 1 are saving 617 acres of forest each year, or 33,000 tons of wood from being burned. Individually, each biogas stove reduces CO2 emissions by four metric tons each year, said Lohani.
The carbon savings are traded by a Swiss-based organization, My Climate, at $18.50 per ton of CO2 equivalent. WWF estimates that the project will reach a break-even point by its seventh year. The average biogas stove lasts 20 years, meaning there will be 13 years of profit after breaking even -- and that much more money to invest back into the area.
Beyond the environmental benefits, the biogas stoves are better for the villagers' health. Constantly burning wood -- many homes burn up to five pounds each day -- fills their homes with smoke and leads to lung and breathing problems. According to the Global Village Energy Partnership (GVEP), air pollution from inefficient stoves leads to 4.3 million premature deaths each year.
Using the stoves is also keeping the area's cattle from grazing in the forests. "The raw material needed for this technology is the dung," explains Lohani. "If you let them go and graze, you'll never get the dung."
Keeping the area's 4.5 million cattle out of the forests is another important step to conserving those areas.
Finally, the leftover sludge from the cement pits is used as a potent fertilizer. It has already helped the farmers create a produce surplus, which is increasing their income.