Life Cycle or Carbon Footprint of Plastic Bags Plastic bags are regarded as one of the most common items in daily life in the modern society. These products continue to be common in everyday life despite emerging concerns across many cities worldwide concerning their probable environmental impact. These concerns have increased in the recent past because of the problem of global climate change. Actually, the concerns have been fueled by increased interest in calculating the climate change effects of varying consumer products in recent years. Despite accounting for a small portion of consumer products, plastic or shopping bags have been identified as sources of numerous environmental problems throughout the world. Some of the major environmental problems emerging from the use of plastic bags include litter, flooding, and resource depletion. Nonetheless, the impact of plastic bags on global climate change can be understood through examining their life cycle or carbon footprint. This is followed by developing possible areas of impact reduction to lessen the environmental problems brought by plastic bags.

Use of Plastic Bags

As previously mentioned, plastic bags are considered as one of the most common items in daily life though they account for a small volume of consumer products. These products are made from non-renewable resources whose major ingredients are natural gas and petroleum. High density and low density polyethylene and linear low-density polyethylene (LLDPE) are the most commonly used materials to manufacture plastic bags (Muthu et al., 2012, p.26). Plastic bags are commonly used by supermarkets as shopping bags and are manufactured from LLDPE to obtain the desired thickness and glossy appearance. These products are usually slender and light, which makes them easy to carry and preferred for shopping. Their use for shopping is also fueled by the fact that they are easy to manufacture.

The use of plastic bags to carry groceries and other consumer goods can be traced back to the 1970s. Since their introduction during this period, they have developed to become popular among consumers and retailers since they are cheap, strong, lightweight, and functional. Retailers and consumers consider plastic bags as hygienic means for carrying consumer goods like food and groceries. Actually, it is projected that approximately 500 billion plastic bags are produced and used by retailers and consumers annually. Consequently, disposed plastic bags are prevalent including in remote areas in the world such as the Pacific Ocean. The prevalence of disposed plastic bags is attributable to the fact that they are discarded as wastes usually after a single use.

Since plastic bags are discarded as wastes usually after a single use, they pose serious environmental pollutions as well as health problems that affect humans and animals (Adane & Muleta, 2011, p.234). The accumulation of these products generates considerable environmental pollution and problems that is manifested in several ways and forms. The environmental impact of these products is more severe in economically disadvantaged regions such as third world countries. Some of the major ways through which the environmental effects of plastic bag wastes are manifested include deterioration of an environment's natural beauty, death of domestic and wild animals, blockage of sewerage systems, increased foul smells, and emergence and prevalence of diseases since they create favorable habitats for insects like mosquitoes and bacteria. In cases where these wastes gain access to agricultural fields, they generate decreased percolation of water and decreased percolation of proper aeration in soil, which lessens the productivity of these fields. The use of plastic bags may also produce some carcinogenic agents as a result of the chemical reactions in their manufacturing processes. According to the findings of recent surveys, the reuse of these products results in cross contamination of foods through microorganisms (Adane & Muleta, 2011, p.235).

Life-cycle Assessment of Plastic Bags

A life-cycle assessment is an analytical tool used by researchers to understand the environmental impact of a product. This assessment is usually carried out from the acquisition of the product's raw materials to its final disposal as waste. This assessment will be helpful in examining the environmental impact of plastic bags since it is an iterative procedure that examines environmental burdens relating to a product, process or activity. The tool achieves this through identifying and weighing energy and materials utilized and released to the environment as well as identifying...

The life cycle assessment of plastic bags relative to its environmental impacts and the problem of global climate change includes
Acquisition of Raw Materials

During the acquisition of raw materials for production of these products, plastic bags consume considerably less energy in comparison to paper bags. The material consumption of plastic bags is 3.12 kilograms with 6.08 kilograms of emissions of greenhouse gases into the Earth's atmosphere (Muthu et al., 2012, p.28). As previously mentioned, the raw materials utilized in the manufacture of plastic bags include high density and low density polyethylene and linear low-density polyethylene. Therefore, the acquisition of raw materials for production of plastic bags generates minimal environmental impacts since these materials have relatively minimal effects on the environment.

Production Processes

The production processes of plastic bags include crude oil extraction and the production of natural gas. The estimated energy requirements in these production processes include resource inputs of natural gas, heavy fuel oil, coal, and diesel. These energy requirements emanate from the fact that plastic bags are manufactured through the use of non-renewable energy resources, particularly petroleum and natural gas. The energy requirements from different resource inputs are generated from exploration, injection, and drilling processes. While the only significant contribution to acidification for production of plastic bags is from refinery and manufacturing, the contribution is relatively lower. The non-renewable energy resources utilized in production of these bags hardly generates any significant environmental impacts. Therefore, the life cycle impact of production of plastic bags in the manufacturing stages and processes are all moderate (Khoo, Tan & Chng, 2010, p.291). In addition, the manufacturing processes of plastic bags are characterized by fewer environmental impacts because of low consumption of non-renewable energy, low emissions of greenhouse gases, and restricted photochemical oxidant creation (Muthu et al., 2012, p.27).

Use and Disposal

The disposal of plastic bags is largely influenced by consumer behavior and governmental policies, which play an important role in this process. Generally, the use and disposal stage of these products comprises three major aspects i.e. disposal to landfill, reuse and recycle. The reuse of a plastic bag until it is discarded or recycled is entirely in the hands of consumers. Disposal of these products, which is most common because they are considered suitable for a single use, is detrimental to the environment with regards to eco-impact. The increased disposal of plastic bags is not only harmful to landfills and agricultural lands but also poses a significant threat to aquatic life (Jalil, Mian & Rahman, 2013, p.2).

Even though the environmental impacts of plastic bags emanate from factors that are not linked to the bags themselves in terms of materials and production processes, their disposal prevent environmental and agricultural growth. This damage is brought by the fact that plastic bags do not decompose with soil and remain in agricultural lands for a long period of time. In essence, plastic bags are either non-biodegradable or decompose very slowly. As they remain in agricultural lands for a long period of time, they end up blocking and hindering the progress of agricultural plants' growth. For instance, while these products are thin, crops fail to pierce through them in order to obtain natural nutrients around the soil. In some cases, these products become fixed to tree and plant branches as they can be easily blown away by air resulting in hindrances to the growth of those plants and trees. Actually, the environmental problems brought by disposal of plastic bags with regards to agriculture include decreased soil fertility, reduction in nitrogen fixation, variance in flora and fauna on soil, significant loss of natural nutrients in the soil, and decrease in crop harvest (Jalil, Mian & Rahman, 2013, p.5). The disposal of these products is also linked to reduced productivity of agricultural lands or fields because of reduced percolation of water and decrease in proper aeration in soil.

Apart from their environmental impacts on agricultural lands, the disposal of plastic bags contributes to environmental pollution and increased health risks. The increased health risks are brought by incidents like blockage of sewerage systems, which implies that people in such areas are exposed to bacteria and other factors that result in increased risk of contacting diseases. Moreover, the carcinogenic agents released during chemical reactions in plastic materials could create more health risks. The health risks also emerge from creation of foul smells and development of favorable habitats for harmful insects like mosquitoes due to disposal of plastic bags to landfills. In addition, disposal of plastic bags causes deterioration of an environment's natural beauty because of environmental pollution. Plastic bags have the capability to leach chemical components and toxins into landfills and water resources, which could become a source of serious health hazards (Adane & Muleta, 2011, p.238). Some of the measures used in disposing these bags…