塑料瓶的碳足迹都是什么？

 The Pacific Institute, a non-profit research organization, estimates that the energy used in the production and use of plastic bottles, such as water bottles, is equivalent to filling the plastic bottles one-quarter full with oil. Oil affects global warming by producing high quantities of greenhouse gases when it is burned. The manufacture of one pound of PET -- polyethylene terephthalate -- plastic can produce up to three pounds of carbon dioxide. Processing plastic resins and transporting plastic bottles are major contributors to a bottle's carbon footprint. The Beverage Industry Environmental Roundtable estimates that one 500-milliliter (0.53 quarts) plastic bottle of water has a total carbon footprint equal to 82.8 grams (about 3 ounces) of carbon dioxide.
太平洋研究所，一个非盈利的研究组织，估算了生产和使用塑料瓶--如水瓶所消耗的能源相当于往塑料瓶里灌四分之一的油。油燃烧时产生大量的温室气体，进而加速全球的变暖。制造一磅的PET聚对苯二甲酸—塑料就能产出3磅的二氧化碳。加工塑料树脂和塑料瓶的运输是塑料瓶碳足迹的主要贡献者。饮料行业的环保圆桌会议估算一个500 毫升（0.53夸脱）塑料水瓶所拥有的碳足迹总和等于82.8克(约3盎司)的二氧化碳。

Transportation of Raw Materials原材料运输

Plastic bottles are made of resins derived from oil or refined petroleum and natural gas. Refined petroleum and natural gas are sometimes transported long distances to the plastic manufacturers, using fossil fuel and producing emissions of greenhouse gases. The size of the carbon footprint depends on the mode of transportation and the distance raw materials have to travel. For example, truck transportation causes more carbon dioxide emissions than rail shipping. When long distances are involved, transportation energy expenditures can approach that of plastic manufacturing and can represent as much as 29 percent of a plastic bottle's carbon footprint.

塑料瓶是由来自石油或精炼石油和天然气的树脂制成的。精炼石油和天然气有时侯要经长途的运输到塑料制造厂，这制造厂就是使用石化燃料并释放温室气体的地方。碳足迹的大小取决于运输的模式和原材料须旅行的距离。例如，汽车运输排放的二氧化碳要大于铁路运输。当涉及到长距离运输时，运输的能源费用可以接近塑料的制造费用，反应到每个塑料瓶的碳足迹可高达29%。

Making Plastic Resins制造塑料树脂

· The manufacture of plastic resins is associated with the greatest amount of carbon emissions, according to the U.S. Environmental Protection Agency. During processing, hydrocarbons in petroleum and natural gas are heated to extremely high temperatures to break down the large hydrocarbon molecules into smaller ones. The small hydrocarbons are then combined in different ways to make various types of plastic. PET resin, resembling grains of rice, is the source material for plastic PET bottles. The energy to produce PET resin represents about 30 percent of the total carbon footprint of a 500-milliliter plastic bottle.

根据美国环境总署的信息，制造塑料树脂与大量的碳排放有关。在加工过程中，石油和天然气里的碳氢化合物要被加热到极高的温度，才能把大碳氢化合物的分子分解成小分子。然后，小分子的烃类按不同的方式化合以制造各种塑料。PET树脂，类似于稻米，是生产塑料PET瓶子的原料。生产PET树脂的能源大约相当于500毫升塑料瓶的碳足迹总和的30%。

Plastic Bottle Production 塑料瓶的生产

· Energy is needed to convert the plastic resin into plastic bottles. Plastic resin, such as PET resin, is melted and injected into a mold, and then heated and formed into the desired bottles. This final process represents about eight percent of a plastic bottle's carbon footprint.

将塑料树脂变成塑料瓶需要能源，塑料树脂，如PET树脂，需熔化并注入模具，然后再加热变成所需要的瓶子。这最后一道工序所占的碳足迹大约是塑料瓶的8%。

Other Variables其他变量

· Cleaning, filling, storing and packaging plastic bottles also uses energy. Waste generation, including carting plastic bottles to landfills, add to the plastic bottle's carbon footprint. The total of these processes can represent 33 percent of the plastic bottle's carbon footprint.

塑料瓶的清洁、灌装、储存以及包装也需要能源。废物再生，包括运输塑料瓶到垃圾填埋场地也会增加塑料瓶的碳足迹。所有这些处理过程将占塑料瓶碳足迹的33%。

Carbon Footprint Calculators碳足迹计算方法

· Carbon footprint calculators for individuals, businesses and even children are available online. Some carbon footprint calculators are free, such as the one by The Nature Conservancy. Calculators for individuals usually address general lifestyle activities and their estimated greenhouse gas emissions. Results from different calculators may vary, because different variables and assumptions are used.

个人的、企业的、甚至是儿童的碳足迹计算方法在网上可以找到。有一些碳足迹的计算方法是免费的，如大自然保护协会的方法。个人的计算方法通常是指一般的个人生活方式及其估计的温室气体排放。不同的计算方法得出的结果不同，因为采用了不同的变量和假设。

Considerations 思考

· Given that production of plastic resin is usually the major contributor to the carbon footprint of a plastic bottle, recycling can reduce the carbon dioxide and other greenhouse gasses by an estimated 30 to 70 percent. Other methods to reduce the carbon footprint are to use less plastic for bottles, making a lighter bottle, reducing transportation distances and other energy intensive processes. Research into other types of plastics and material that is not derived from fossil fuel could lead to a smaller carbon footprint of the plastic bottle.

鉴于树脂塑料的生产一直是塑料瓶碳足迹的主要贡献者，回收可以将二氧化碳和其他温室气体降低至约30--70%。另外一个减少碳足迹的办法是少用塑料瓶，制造更轻的瓶子，减少运输距离以及其他耗能的流程。研发其他形式的、不是来自石化燃料的塑料和材料，这样也可以减少塑料瓶的碳足迹。