New Scientist: TALK about killing two birds with one stone. Every year we ditch millions of tonnes of chicken feathers, and pump climate-altering carbon dioxide into the air. But combine the two in the right way and you can make an otherwise-scarce fertiliser. More than 5 million tonnes of chicken feathers are produced globally every year. Most get thrown into landfill where they can sit for decades without breaking down. Changle Chen of the University of Science and Technology of China in Hefei, Anhui Province,...