Greener Green — The U.S. One Dollar Coin

The Sacagawea dollar coin was introduced in 2000 to replace the Susan B. Anthony dollar, which (being Canadian, I didn't know) was often confused with the quarter because of its color and feel. The newer coin is a golden color with no ribbing along the sides to prevent confusion, just like the Presidential coins introduced this year by the US Mint . When the coins were introduced, Michael Claus, W. Reid Shepherd and Brandon Wayne at Michigan State University asked "is one form of the dollar better for the environment? If the coin dollar is better, should we replace the paper dollar with its coin equivalent? If the paper dollar is better, and Americans trust the paper dollar more than the coin, wouldn't it be prudent to stop introducing new coins into the American economy?" Their answer: the coin is better.

Their study tried to examine the life cycle of the coin dollar and the paper dollar (note) to determine if one was better for the environment. On the economic front: the dollar note costs 4 cents to produce with an average lifetime of 18 months. The dollar coin costs 8 cents with an average lifetime of 30 years. Information was collected from the United States Federal Government through the Department of the Treasury, the Bureau of Engraving and Printing, and the United States Mint. To prevent counterfeiting, these sources did not provide all details to the process, requiring some assumptions about the process to be made. However, the most important observations include the lifetime for the coin and note, 30 years and 1.5 years respectively, and the recycling and disposal of the two types of dollars. The coin is completely recycled into the production process after leaving circulation, where 90% of the dollar note is placed in landfill after leaving circulation and the other 10% is recycled as ROOFING SHINGLES! They recommended that the one-dollar note be phased out and completely replaced by the coin dollar.

"The paper note is made from 75% virgin cotton 25% linen blend of paper, and industrial oil based ink is used to produce the coloring on the paper. A reusable metal plate is used to imprint the design on the note. Only non-recycled cotton and linen may be used in the printing of the paper note. The paper dollar is bleached and shredded after circulation and only 10% is recycled as roofing shingles. The other 90% is placed in landfills The coin dollar is made from 88.5 % copper (Cu), 6% zinc (Zn), 3.5% manganese (Mn), and 2% nickel (Ni). The process allows for a complete recycle of the metal used to manufacture the coin, including the final coin when it comes out of circulation and all metal waste from the process itself."

Although this study is well-intended, these folks delve into a complex process that is highly restricted by Acts of Congress: processes can't be changed unless by an Act of Congress and the details of production processes and the true composition of both coins and notes are confidential to prevent counterfeiting. They have also left out the energy requirements for raw materials extraction of the metals for the coin and the cotton and linen for the note. It would be interesting to compare these energy requirements and environmental impacts. However, the general conclusions based on the fact that the coin has a 30-year life cycle and can be completely recycled, while the note only lasts for 18 months leads us to believe that they are correct despite the lack of information. Wouldn't it be great if the U.S. Mint was doing an in-house life cycle assessment of these two options with all of the correct data? I'll wait to read that LCA even if it is blanketed with black marker. Read their study >here. Images courtesy of the US Mint .