Research On Assessment And Control Of Carbon Emissions For The Cotton T-shirt Supply Chain Based On Life Cycle

China is the largest exporting and producing country of apparel, and apparel supply chain plays an important role in the national economy. However, apparel industry is still in the extensive management mode, and the problem of high pollution and high emission is very serious, which has a bad influence on natural resources and society. And researches standing at the point of apparel supply chain are very rare, so it’s very necessary to provide a system method of measuring the carbon emissions of apparel supply chain.This paper uses life cycle method to measure the carbon emissions of cotton T-shirt supply chain, and uses system dynamics to simulate the carbon process, and the result is useful to provide corresponding policy advice. Firstly, on the basis of analysis of cotton T-shirt supply chain and its carbon structure, this paper divides cotton T-shirt into five processes:transportation process, cotton cloth producing process, cotton T-shirt manufacturing process, warehouse process and sale process. Then it analyzes the five processes and their unique characters in details, and gives the calculation method of carbon emissions. Secondly, this paper builds causal diagrams of transportation system, manufacturing system and sale system. Thirdly, it builds the carbon emissions model of cotton T-shirt supply chain using system dynamics method, measuring the carbon emission of a piece of cotton T-shirt and simulating the carbon emissions of the five processes and the total carbon emissions from2006to2013. Finally, it looks the changes of the carbon emissions of cotton T-shirt supply chain by changing transportation factor, energy factor, wasting factor and package factor, and it gives some useful advices according to the results.Result shows that the carbon emission model of cotton T-shirt supply chain based on system dynamics is accurate and feasible. It can not only measure the carbon emissions of cotton T-shirt supply chain, but also observe the effect by changing some factors. It turns out that it produces11.16kg CO2producing a cotton T-shirt of250g. And transportation process produces1.69kg CO2, and cotton cloth producing process produces7.47kg CO2, and manufacturing cotton T-shirt process produces1.68kg CO2, and warehouse process produces0.02kg CO2, and sale process produces0.3kg CO2. The ratio of cotton cloth producing process and manufacturing cotton T-shirt process is82%, and the ratio of transportation process is15%, and the ratio of warehouse process and sale process is3%. Result show that the carbon emissions of cotton T-shirt supply chain can reduce to34%by using wind power or nuclear power, which is very important way to reduce carbon emissions. Change of transportation factor or wasting factor, it can reduce1067.3t or864.7t carbon emissions, which is also an important way to reduce carbon emissions. By using once or twice recycled package, it can reduce41.2t or61.8t carbon emissions. Although the effect is not very obvious, it’s the easiest way to realize, which makes it also an important choice.