The natural environment of the earth provides critical platform upon which all life based. Ecosystems provide regulating as well as supporting services that are essential for food production. Agriculture provides food to the rapidly growing global population of the world. It also remains the largest driver of environmental damage in the following fields: genetic erosion, conversion of natural habitats and species loss. Likewise, the environmental impacts of escalating food demand will depend on the direction which global agriculture takes.
Environmental Implications Due to Increase of Demand for Food in the World
According to Wesseler (2005), agriculture’s greenhouse gas release in the atmosphere will double by 2050 due to global food production demands. Over four thousand assessed plants and animals are threatened by agriculture intensification, and the number is still rising. There are overfishing and destructive fishing methods due to eutrophication caused by high nutrient run-off from agricultural areas (Todd 1980). Global food demand could double by 2050. Land clearing emits greenhouse gases, which also threatens species with extinction.
Factors Causing Environment Impacts Due to Increased Food Demand
Deforestation refers to the removal of trees on a large area. It is a clearing of land for agriculture to meet demand for food. Deforestation causes risk for many wild crops mainly due to the loss of habitat, facilitates environmental degradation and land fragmentation, which causes extinction of many other species. It also causes soil erosion with nitrogen fertilizers that drain into the seas, rivers and ocean facilitating growth of aquatic plants like water hyacinth. Aquatic plants, such as water hyacinth, reduce oxygen and light penetration in water. According to Timberlake (2009), increase in global land clearing will total to an approximation of one billion acres of land by 2050; global agricultural greenhouse gas emission will total to an approximation of 3 Gt y?1 of CO2-carbon equivalents, and global nitrogen use to an approximation of 250 Mt y?1. These increases will have major environmental impacts, such as species extinctions, loss of ecosystem services, increased level of greenhouse gases in atmosphere, and water pollution.
Climate Change and Agriculture
Both climate change and agriculture are processes that interrelate ad take place in the ecosystem. Global warming through agricultural processes determines the carrying capacity of the atmosphere to produce an adequate amount of food (Karl 2009). Increased carbon dioxide level due to increased agricultural practices has both detrimental and beneficial effects on the crop yields. Agriculture produces significant effect on the climate change due to release of greenhouse gases, such as carbon dioxide gas, in the atmosphere.
The use of genetically modified crops has a major concern in insect control through expression of vegetative insecticidal proteins genes from Bacillus thuringiensis. Vegetative insecticidal proteins are toxic, which can affect non-target predators and other beneficial or harmless insects, as well as the targeted pests. According to Wesseler (2005), the widespread use of modified genetic design leads to over-use of chemicals that damage environment and biodiversity. In genetic engineering, pests evolve to become resistant to pesticides due to mutations in their genetic makeup. Mutations make them survive and reproduce to an extent that is uncontrollable.
Environmental impacts of irrigation occur due to changes in the quality and quantity of soil and water as a result of irrigation to produce food for the increasing population. Irrigation leads to a number of problems, such as insufficient irrigation that results to poor soil salinity control with consequent build up of toxic salts in the areas with very high evaporation levels (Bruce 2007). Overpopulation and poor management of waste waters and chemicals leads to the water and land pollution, which may cause habitat loss of threatened organisms in the environment.
The environmental impact of pesticides consists of the effect of use of pesticides on non-target species. Misuse, overspray of insecticide and herbicides causes soil, water, air, and land pollutions. Pesticides and herbicides react with other chemicals in the air to form a pollutant called tropospheric ozone, which causes greenhouse effect. Pesticides carried by rain water runoff into rivers, seas and ocean cause water contamination. Application of pesticides and herbicides into water bodies causes death of aquatic organisms. It is because dead aquatic organisms decay, thus consuming oxygen from water, which makes living organisms like fish suffocate.
The use of plastic materials in agriculture provides habitat for mosquitoes. It causes spread of malaria, which represents danger to people.
Biological Pest Control
Use of biological control is a method of controlling pests through the use of other living organisms, for example, the use of predators, herbivores, parasites and other natural mechanisms as biological control agents. Biological pest control prevents use of chemicals that pollute the environment.
Organic farming is the use of agriculture that relies on natural methods, such as green manure, biological pest control and crop rotation. Organic farming reduces land, water, and air pollution. It restores, maintains and enhances ecological harmony. Hence, organic farming reduces the use of nitrogenous fertilizers, which cause eutrophication in water bodies.
Sustainable agriculture is the use of integrated agriculture that has environmental health and economic profitability, and social and economic equity. For example, agroforestry may be used to produce food and to create habitats for wild organisms.
Reforestation is planting of trees in areas, where clearing of the land was done to engage agriculture. Reforestation creates habitat for many organisms, restores biological cycles, and reduces soil erosion and water pollution by reducing surface runoff. It also produces food for a growing population of living organisms in the environment.
Government should create awareness through seminars, shows and exhibitions on how to keep the environment clean.
In conclusion, governments should create awareness among farmers for them to understand the future environmental effects of global crop production, to understand how to achieve greater yields with lower impacts to the environment, and how different production practices affect yields and environmental variables. Farmers should use an alternative source of food production without damaging environment to preserve biodiversity and other natural resources. Habitat modification in agriculture increases risk of species extinction (Winter & Gallegos 2006).