The population explosion in the 21st century will have a severe impact on the problems associated with food supply and the environment. Even at present, the shortage of food protein resources is an acute problem. Effective countermeasures to cope with the ever worsening shortage of protein resources in the next century are absolutely essential. We have developed methods to produce and isolate single cell proteins in an ample yield. We have also found that among food grains rice has the highest protein content, and have found that the protein in the grain is present in discrete particles, for which we coined the name“protein bodies”. Rice protein has a relatively good balance of essential amino acids, and hence a relatively high nutritional value. We were able to increase the nutritional value further by fortifying it with L-lysine by a novel soaking method. New methods of food preservation will be important to cope with the 21st century food problems, because a large amount of food is lost either on the farm or during storage, to microorganisms, rodents and insects. We developed the carbon dioxide exchange method (CEM), in which food is stored under CO₂ in hermetically sealed containers (called Hibernation Rice). CO₂ is reversibly adsorbed to, and desorbed from the amino groups of food proteins. We also developed underwater and underground food storage methods earlier (1967-72), to take advantage of constant low temperatures in these conditions. Based on these studies, large scale storage methods in 200kg steel drums in CO₂ have been developed On an industrial scale which is operated on a commercial base. Methylbromide destroys the ozone layer, and will be banned completely from use for food preservation or any other purposes. Storage under CO₂ is far superior to methylbromide because CO₂ completely eliminates the rice weevil and otherinsects, has no toxicity or public health problems, and is economical. CO₂ is a very effective synergist when used with the pasteurization gas, ozone, to sterilize foods against the virulent pathogenic strain of E. coli, O-157 and black pepper which are known to be contaminated with bacteria. The use of CO₂ may add to an already high production of CO₂ from other sources, such as combustion of fossil fuels. Effective measures to prevent leakage of CO₂, are needed. We are striving for an innovative idea to prevent the escape of CO₂ and the consequential warming of the earth.