Engineers without Borders works to build things such as systems to collect rainwater and photovoltaic solar cells to provide power in health clinics. Read more about engineering with heart.

Even if you are not overweight, you should slim down to reduce your risk of cancer, according to a 2007 study by the U.K.'s World Cancer Research Fund.

As Earth becomes more urbanized, it be better off, according to George Martine, lead author of the 2007 State of World Population report. Are cities best for earth? Read more.

NASA's Molly Brown developed a Famine Early Warning System Network. Brown talks about this life-saving technology in this 8-minute podcast.

India is now the world's second-most-populated country, next to China.

David Carroll is getting closer to creating a new kind of solar cell, one made of plastic that would be lightweight, flexible, and more efficient than the more familiar silicon solar cells. Read more about how nanotechnology is improving solar cell efficiency.

He has created a device that could help doctors identify what are called "oncoproteins." This research might eventually enable doctors to better diagnose and treat early-stage cancer.

It seems obvious there's economic value in nature's raw potential for goods. But nature has other, perhaps less obvious, economic value, said economist Scott Barrett.

Ethno-botanist Darron Collins talks about rainforest logging. It may be more sustainable, but it'll take much more to save the rainforests. Read more.

Partha Dasgupta told Earth & Sky that, in the developing world, natural resources aren't just amenities. Instead, they're economic necessities.