There’s a ubiquitous crop that slurps up unsustainable quantities of water, gets doused in chemicals and fertilizers to maintain its growth—and yet doesn’t provide us with any food. This crop is cotton, and it covers 34.5 million hectares of arable farmland around the world. Now, a team of Swedish researchers propose that if we replace a share of this crop with fibers made from the wood of fast-growing poplar trees, we could free up millions of hectares of cotton land for growing food instead. They also explore how a new processing method could make use of the whole tree, extracting bio-oils for fuel from the remaining wood. To boot, poplar forests could help to draw down carbon as they grow, the researchers report in the journal Joule. …Fast-growing poplar trees are a good source of cellulose—and they don’t need cotton’s artificial inputs.