linage compressions: Inhabitat's Week in Green: madder root batteries, sun-powered plane and the world's first fiber-optic solar cell

Each week our friends at Inhabitat recap the week's most interesting green developments and clean tech news for us -- it's the Week in Green.

This week held some truly unexpected breakthroughs as scientists in China figured out a way to create brain cells from human urine, and researchers at Rice University and CUNY developed batteries that are fueled by the dye from madder roots. Over in Germany, researchers unveiled a technique that harnesses the power of lightning to break up concrete into usable building materials and scientists at MIT built a tiny, caterpillar-size robot that can transform into almost any shape.

We've been hearing a lot of bad news about the environment such as climate change throwing natural systems out of balance, but things could be looking up slightly. Last week at the Doha climate conference, 200 nations agreed to extend the Kyoto Protocol to 2020 and back in the US, a report showed that Americans installed a record-breaking 3.2 gigawatts of rooftop photovoltaic panels in 2012. And if all else fails, Harvard professor David Keith, proposes geo-engineering as a way to combat global warming with his plan to refreeze the Arctic.

linage compressions