Global warming and climate change are currently great concerns in the face of a dim future in the field of food security. Clearing of forests and the green cover for development, settlement and industrial establishment heightens the gravity of the impending crises. Even with these in the offing, current debate concerns food and sustainability, especially between the proponent of plant-based diet as the best option for food and sustainability and proponents of meat and dairy-based diet. Meat and dairy-based diet proponents aver that the products offer rich nutrition value and that the production of the products through animal husbandry requires less land in comparison with human development. The idea of food production and sustainability, however, is not about the comparison of the extent of destruction caused by human development, but rather the idea of sustainability in food production. Plant-based diets have the capacity to fulfil all the human nutritional needs while ensuring environmental sustainability. Plant-based diets, therefore, offer more in sustainability and argument against them by meat and dairy-based diet proponents fails to appreciate the precarious path that the current levels of global warming and climate change have on future generations.
Food and Sustainability
Environmental change and global warming pose a threat to the world today. Rising temperatures, increase in greenhouse emissions, melting of ice in the North Pole, erratic weather changes and the rising water levels in seas are evidence of climate change in the world. The environmental changes are a huge concern to humans and, therefore, they call for an immediate change in human behavior towards environmental sustainability. From the rising of environmental sustainability stem arguments regarding plant-based and meat and dairy-based diets. Current concerns for environmental sustainability stand even as estimates on diets indicate that four billion people worldwide live exclusively on plant-based diet, while two billion live primarily on meat-based ones (Pimentel & Pimentel, 2003). The number of people consuming meat and dairy-based diet is alarming, given the rapid population growth and its impact on the food chain. Therefore, it is essential to advocate for a plant-based diet as a measure of food sustainability while shunning meat and dairy-based diet, given its adverse impact on the environment through deforestation and contribution to global warming.
At the center of the current diet patterns across the globe is the long-debated topic of sustainability. Sabate and Soret (2014) argue that sustainable diets are those “with low environmental impacts which contribute to food and nutrition security and healthy life for present and future generations” (p. 476). That is, a sustainable diet guarantees food not only to the current generation but also to the future ones. Therefore, it is important to adopt sustainable diet practices to protect the future generations. Sabate and Soret (2014) further assert that such diets are “protective and respectful of biodiversity and ecosystems, culturally acceptable, accessible, economically fair and affordable; nutritionally adequate, safe and healthy; while optimizing natural and human resources” (p. 476). In light of the threshold for sustainable diets, Fanzo, Cogill and Mattei (2012) argue that for any sustainable diet, it should have nutritional adequacy, environmental sustainability, be accepted culturally and be available at low cost.
With the threshold that satisfies the measure of sustainability, it is vital to compare levels of sustainability between plant and meat/dairy diets. Researchers have conducted numerous studies comparing environmental impact and durability of the two diet categories with their drawbacks and adverse impact on natural resources such as land, water and energy. Producing meat and dairy is an inherently inefficient process considering the amount of land and other input required for production of meat and dairy products (Sabate & Soret, 2014). A comparison of the amount of land necessary for the production of similar amounts of meat-based and vegetarian-based diet paints a grim picture for meat-based diets. According to Pimentel and Pimentel (2003), less than 0.4 ha or cropland is necessary for production of a vegetarian-based diet (450 kg) in comparison with more than 0.5 ha of cropland used to produce a similar amount of meat-based diet. The comparison highlights the vast land needed in the production of a meat-based diet.
A large amount of land required for livestock farming and rearing poultry is further highlighted by the comparison between how much land is necessary for producing 100kg of cheese. In their research to compare the amount of land required for producing cow milk-based cheese and lupine-based cheese, Reijnders and Soret (2003) discovered a huge difference in land requirements for the two. From the research, 100kg of lupine-based cheese required 0.02 ha of land, while the same amount of cheese based on cow milk required 0.1 ha of land (Reijnders & Soret, 2003). Compared with the amounts of land required for production of cattle-based cheese, such land requirements are not sustainable and only lead to the clearance of forest land, felling thousands of trees, to make room for ranges for rearing the animals. Sustainable diet not only fulfils nutritional requirements of an individual but also guarantees environmental sustainability and is cost-effective. Reijnders and Soret (2003) aver that while only 10 grams of vegetable protein is required for producing 1 gram of animal protein, animal protein production is an intrinsically difficult affair, given the differences in meat production from different animals. Protein production from soybean requires a 6-17 smaller land units than meat production. An additional resource that comparative analysisis show inefficiencies in their use during the production of animal protein in comparison with plant protein is water. As a natural resource that is depleting and one that is essential for both human and animal life, careful water usage is at the heart of environmental sustainability (Reijnnders & Soret, 2003). Comparisons on the amount of water required for producing a gram of animal protein and plant protein paint a negative picture of animal protein consumption of water. According to Shepon et al. (2016), livestock farming requires a lot of water. Gravity of the inefficiency is evident from the fact that it requires 1.5 times more water in producing one gram of protein from milk or eggs than the production of a gram of protein from plants (Shepon et al., 2016). The situation is worse when compared with the amount of water required for the production of a calorie from animal products as compared to the ones from plants (sugar). It takes three liters of water to produce a calorie from animal products in comparison to only 0.5 liters of water for plant produce from starchy roots. Calories are an important source of energy for humans (Shepon et al., 2016). Therefore, to attain the recommended calorie intake per day from animal products, one would need to use more animal products, which exerts exigencies on the available water resources.
Fuel efficiency and the resulting greenhouse gas emission from animal husbandry for production of animal protein pose a significant threat to the environment. Animal husbandry is not only fuel-inefficient but also uses more fossil fuel, which is a natural resource. Reijnnders and Soret (2003) argue that regardless of the relative intensities of the agricultural practices employed in addition to the attribution of the energy inputs used in producing foods, “the efficiency of fossil fuel use may be a factor that is 2.5–5 times better for vegetable proteins, if compared with animal husbandry” (p. 666S). The difference in energy efficiency is higher in regions that have advanced agricultural practices, whereby the factor of efficiency in use of fossil fuel ranges between 6 and 20, with the advantage going to production of plant protein such as soyabean (Van & Krutwagen, 2001).
The use of fossil fuels and other inefficient means of production have been, at the forefront, towards increasing the amount of greenhouse gas emissions into the atmosphere, consequently increasing global warming. Moreover, research indicates that dietary patterns have a huge role to play in the increasing environmental degradation (Berners-Lee et al., 2012). Replacing meat and dairy products from a diet, according to Sabate and Soret (2014), had a marked reduction in the emission of greenhouse gases. The research indicates that vegetarian diets reduce greenhouse gas emissions by up to 22 per cent, while vegan diets contributed to 26 per cent reduction in greenhouse gas emissions (Sabate & Soret, 2014). Other positive estimates indicate that continued vegan diet would reduce greenhouse gas emissions by 48 per cent within the agricultural food production system as well as 34 per cent in the overall food system greenhouse gas emissions (Sabate & Soret, 2014). The evidence and estimates presented point only sustainability in food production system but also on an improved environmental outlook by adopting vegetarian-centric diets.
Proponents of the use of animal proteins and other dairy products posit that animal husbandry demands little inland for expansion in comparison with human development. They argue that human development has high demands for spaces for residential, office or factory construction. The construction industry alone releases about 40 million tons of carbon dioxide, in addition to other toxic substances such as acid gases and oxides of nitrogen (Dixon, 2010). The release of greenhouse gases and other harmful substances into the environment, nonetheless, is dismal compared to the impact building constructions have on the ecosystem. Therefore, human activities degrade the environment significantly compared to animal husbandry for animal diet. While it is true that human activities such as construction of buildings immensely contribute to environmental degradation in addition to contributing to greenhouse gas emission, animal husbandry is a major contributor of soil erosion. Pimentel and Pimentel (2003) aver that animal husbandry leads to soil erosion and degradation. Pasturelands and rangelands are among the lands with the highest rates of soil and fertility loss, at 13 times higher rates than croplands (Pimentel & Pimentel, 2003). Moreover, more than 60 per cent of the pasturelands experience overgrazing and, therefore, are subjected to increased erosion (Pimentel & Pimentel, 2003). Overgrazing and soil erosion is a recipe for desertification, which is among the major contributors to environmental change and global warming.
Nutritional experts support the use of animal meat and dairy products for their calorific efficiency. Rodriguez (2012) argues that in comparison to vegetarian or vegan lifestyles whereby individuals are at a risk of becoming obese or malnourished, meat and dairy products allow the individual to obtain essential nutrients without necessarily taking excess calories, such as those found in starchy foods. Additionally, Rodriguez (2012) argues, stopping the intake of dairy products has the risk of negating intake of necessary vitamins, including vitamin D, protein, vitamin B12, zinc and iron, most of which are derived from animal products. Animal diet proponents further argue for the manure content from animal droppings and the role of the droppings in improving soil fertility.
Research has proven that vegetable protein is an adequate replacement for meat, fish and dairy products in supplying the body with the necessary nutrients. Moreover, there are several adaptations available for enriching vegetable proteins, including the lowering of minerals like phytate and adding trace elements, as well as vitamins. The addition of such elements has minimal environmental impact while supplying the necessary body nutritional demands (Reijnders & Soret, 2003). Furthermore, the argument that the animal droppings add to soil fertility, while true, does not hold ground in continued animal husbandry. Aside from contributing to soil erosion, the droppings take long before their integration into the soil in comparison with integration of vegetative material into the soil.
Environmental change and global warming are issues that will continue to plague the world, especially as humans strive towards meeting their basic needs and luxurious wants. If steps are not taken to address this issue, then most likely resources will be depleted eventually, which will have significant adverse effects on all life forms. Greenhouse emissions from manufacturing and other human activities continue to burden the environment and increase global warming. In food patterns, animal-based diets have proven catastrophic and unsustainable to the environment, as they not only consume large amounts of natural resources for production but also prove to be inefficient and wasteful. Moreover, clearing forests for animal husbandry are among the activities leading to climate change. However, plant-based diets have proven efficient and sustainable, contributing to the reduction of global warming and greenhouse gas emissions. While many continue to laud the calorific and nutrition value of animal-based diet, the truth is that plant-based diets have similar calorific and nutritional values. Consequently, plant-based diets are not only nutritional but also essentially sustainable as they are efficient in the use of water and other natural resources, apart from contributing to the reduction of greenhouse gases and global warming.
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