Researchers at the American Chemical Society have further suggested that aquaponics would be an ideal socially-acceptable solution in the post-contamination environment, as it does not use soil to grow fish and vegetables, thus completely alleviating the radiophobia surrounding food that always follows long-lived contamination incidents. Others who have approached the food problem from a far more extreme view, assuming far worse events such as comet impacts, as discussed in the book "Feeding Everyone No Matter What", have suggested; natural-gas-digesting bacteria the most well known being methylococcus capsulatus, that is presently used as a feed in fish farming, Bark bread a long-standing famine food using the edible inner bark of trees once a part of Scandinavian history during the Little Ice Age and the expansion of leaf protein concentrate and larger scale wood digesting fungiculture for fungal protein, with the most common of which being shittake mushrooms and honey fungi, as they do not need sunlight or soil to grow. More advanced techniques mentioned, that are not presently economical also include variations of wood or cellulosic biofuel production, which typically already creates edible sugars/xylitol from inedible cellulose, as an intermediate product before the final step of alcohol generation.