A US startup claims it can convert CO2 into nutrients, leading to air-based “meat”. Developed by Air Protein, the technology is based on an idea conceived by Nasa in the 1960s as a possible way to feed astronauts in space. Given most meat-free meats are based on soy or other plant proteins, which have their own land-use footprint, this technology would have the environmental advantage of being made inside fermenting units. With a growing demand for meat alternatives there will no doubt be increasing interest to see whether innovations such as this could effectively contribute to a sustainable food future.