Climate change and dietary choices - how can emissions of greenhouse gasesfrom food consumption be reduced?

Results from an analysis of greenhouse gas emissions and energy consumption during the life-cycle of carrots, tomatoes, potatoes, pork, rice and dry p eas consumed in Sweden are presented and discussed. The life-cycle is delin eated to the part of the production chain prior to purchase by the consumer . The study shows that emissions, expressed in g CO2 equivalents, are highe st for pork and rice and lowest for potatoes, carrots and dry peas. The mos t important stages of emissions in the life-cycle are identified for each o f the different food items, Crop farming is the most important stage for ri ce and tomatoes while rearing of animals is the most important stage for po rk and storage is the most important stage for carrots. Comparison with an energy analysis shows that important stages in the life-cycle of food may b e under-evaluated when energy only is accounted for. This may lead to a sub -optimisation of pollution control exemplified by the case of transportatio n. Also, it is shown that the choice of functional unit has a decisive infl uence on the outcome of the study. The recommendation is to compare whole m eals, or diets with the same nutritional qualities. A comparison of four me als composed of the food items under analysis shows that a meal with tomato es, rice and pork has nine times higher emissions than a meal made from pot atoes, carrots and dry peas. Emissions of greenhouse gases from consumption patterns based on the food items analysed are compared with an assumed sus tainable limit of greenhouse gas emissions. The conclusion is that current food consumption patterns in the developed countries exceed the level of su stainability by at least a factor of 4, Prospects for achieving sustainable food consumption patterns are questionable in view of current trends in fo od demand. (C) 1998 Elsevier Science Ltd. All rights reserved.