Clean By Design: Transportation
Today, raw materials, manufacturers and retailers are routinely located on opposite sides of the globe. In fact, according to the American Apparel & Footwear Association nearly 98 percent of all apparel items bought in the United States are imported from abroad. To move garments from factory to market, each designer and retailer has to choose between different transportation options. While each of these methods will impact the environment in some form, apparel retailers and brands can make informed transportation choices to significantly reduce their pollution footprint and save money.
Some top retailers and brands have already successfully reduced their pollution emissions and improved their bottom line this way. By changing their shipping practices, Continental Clothing (a UK-based retailer) reduced greenhouse gas-emissions from transporting some of their products by 90 percent. And Macy's started saving $1.75 million per year when they reduced the number of empty trucks on the road.
There are many simple choices retailers and designers can make to decrease the impact of global transport, reduce carbon emissions, and help protect public health.
1. Avoid air transport whenever possible.
Airplanes emit significantly more pollution than any other transportation method, while rail and ship emit far less (see Figure 11). As shown in the case study below, greenhouse-gas emissions from transporting goods across the ocean can be reduced by 99 percent in some cases simply by sending cargo via ship instead of a plane. Every ton moved by plane instead of ship adds over 4.5 times more particulate matter and nearly 25 times more nitrous oxides to local environments.
Continental Clothing implemented a transportation strategy that reduced greenhouse gas-emissions from some of their products by 90 percent. The reason? It committed to a "No Airfreight" policy.
2. Pick the type of ship wisely.
When it comes to oceangoing ships, the type of vessel your company chooses can greatly lower the emissions impact of moving your garments around the world. Using a more fuel-efficient ship can reduce carbon-dioxide emissions by up to 53 percent, according to shippingefficiency.org, a database of ship rankings maintained by the nonprofit organization Carbon War Room. Look for Grade A ships.
Some oceanic shipping companies are adopting a practice called "fuel switching", where vessels run off low-sulfur fuel in their auxiliary engine near ports, and only switch to main engines on the open ocean. This practice reduces soot emissions, which are very damaging to human health. The shipping giant Maersk has been piloting and promoting fuel switching since 2006 when Maersk line ships first started using a fuel switch within 25 nautical miles of all California ports. The practice lowered Maersk's near-port soot emissions by 86%.
Many governments are now beginning to institute fuel switching around major ports and coastlines. The US and Canada are phasing in a North American fuel switch zone to compliment similar requirements in the North and Baltic Seas. Industry-led collaborations are also on board; to demonstrate their commitment, 16 major freight liners have joined the Fair Winds Charter to voluntarily reduce near-shore emissions in Hong Kong.
3. Consider the route.
Calculating emissions from different potential routes is an important way for retailers and designers to think through the impacts of each freighting decision. Rough estimates can be made using the emission factors from Figure 1. One example of this approach is found here (insert link to case study). Retailers can also use tools such as OOCL's Carbon Calculator, which shows the CO2 emissions for each leg of a shipment's journey.2
In 2008, Levi Strauss reviewed and altered its international shipping routes. It used less air and truck transport, and increased rail and ship usage. Many routes decreased greenhouse-gas emissions by 50 percent to 60 percent. By 2009, Levi Strauss' shipping practices emitted 700 fewer metric tons of carbon dioxide per year.
Some U.S. retailers are also reducing their trucking emissions by collaborating with other businesses to reduce "empty miles," which is known in the industry as the second leg of a round trip. Those who ship by truck can use the Voluntary Interindustry Commerce Solutions Association Empty Miles program. Through the program, Macy's no longer runs an empty round trip leg on 21 percent of its trucking routes, says Bill Connell, Macy's senior vice president for transportation of reverse logistics and collaboration. It's saving the company about $1.75 million per year.
Case Study: The Emissions of One Container
|Table 1. Air Emissions per Ton-Mile3|
|grams of CO2e/Ton-Mile4||119||40||11||1,193|
|mg of NOx/Ton-Mile||318||367||158||3,944|
|mg of PM10/Ton-Mile||92||13||25||1195|
A common route for a cotton garment in the United States begins in the western Chinese province of Xinjiang -- where 1/3 of Chinese cotton is grown – continues through a coastal manufacturing and shipping hub like Shanghai or Guangzhou, then ends in the United States. Table 1 presents important emissions factors for each transportation mode.
Using these factors and calculated distances, Table 2 summarizes the emission from shipping a 20ft intermodal container of cotton from Urumqi, Xinjiang to Denver, Colorado (calculated for roughly 16 tons of cotton6, which could be spun into roughly 82,000 t-shirts7).
|Table 2. CO2 Emissions for a Shipping Container
of Apparel from Chinese Field to American Store
|Xinjiang to Shanghai||Shanghai to Los Angeles||Los Angeles to Denver|
|Kg of CO2e||3,656||1,357||950||96,618||1,550||575|
|Kg of NOx||12.7||16.5||17.0||418.8||5.4||7.0|
|Kg of PM10||3.7||0.6||2.7||12.7||1.6||0.2|
In this scenario, the truck-air-truck pathway emits over 5 times more soot (particulates) and 35 times more greenhouse gases than rail-ship-rail, sending an additional 99 tonnes of greenhouse gases into the air. On the ocean leg alone, a retailer would reduce GHG emissions by 99% sending cargo by ship instead of plane. Using this method, a retailer could send 101 full containers by ship and still emit fewer GHGs than one container sent by plane.
- The specific emissions numbers in Figure 1 can be used as general guidelines, but actual emissions depend on a wide range of factors, including vehicle condition, route taken and fuel efficiency. Emissions from a given type of transportation will also vary by country. For example, trains in the United States use diesel engines, while European trains run on electric power, which pollutes less.
- Efficiency figures for Truck and Air from: EIA, "Annual Energy Outlook," 2011, tables 66, 68. Efficiency figure for Rail from: DOE, "Transportation Energy Data Book," Ed. 29, 2010, table 2.16. Efficiency figure for large container ship calculated from EMEP/EEA, "Emission Inventory Guidebook 2009," updated Mar 2011. Emissions factors for Truck, Rail, and Air for CO2, N2O, CH4 from: EIA, "Documentation for Emissions of Greenhouse Gasses in the US 2005". PM10 emissions factors for Air and Truck adapted from Facanha & Horvath, "Evaluation of Life-Cycle Air Emission Factors of Freight Transportation," Environmental Science Technology, 2007, v. 41 p.7138-7144. PM10 emission factor for Rail from EPA, Technical Highlights: Emissions Factors for Locomotives, 2009, Table 6. Emission factors for ship from: IMO, "Second IMO GHG Study 2009," Table 3.6. Upstream fuel and feedstock emissions from: Argonne Labs, GREET 1.8 model.
- Includes CO2, N2O, and CH4 weighted according to IPCC, Climate Change 2007 Technical Summary, Table 2.14, p.33- 100-yr global warming potential of N2O is 25 times greater than CO2 and CH4 is 298 times greater than CO2.
- The public literature does not currently have a PM10 factor for in-flight air emissions, only LTO, or landing takeoff cycle, data is available; this factor is based on LTO data and expanded to PM10/ton-mi by Facanha & Horvath 2007.
- Assuming a Gin Universal Bale with density of 28lb/ft3 from the Joint Cotton Industry Bale Packaging Committee, "2010 Specifications for Cotton Bale Packaging Materials," www.cotton.org/tech/bale/specs/upload/2010-Specs-FINAL.pdf
- Pietra Rivoli uses a conversion factor of about 0.4 lb of cotton per t-shirt in Rivoli, Pietra, The Travels of a T-shirt in the Global Economy, 2nd ed., Hoboken, NJ: John Wiley & Sons, Inc., 2009, p.4, 50.
last revised 2/5/2012
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