How much does it really cost (the planet) to make a penny?
Ah, the lowly penny, the one-cent coin graced by Lincoln's face, is often fountain fodder and city litter. Kids love to fill their piggy banks with them and untold billions are in collection jars and other forgotten places.
Most people know that pennies cost the government more to make than they're worth. They may not know that making all those pennies has a serious environmental impact.
With that in mind, is it possible to make the penny greener?
Christina Cogdell, an associate professor of design at the University of California Davis, asks her undergraduate students to parse out each material comprising a particular product. Two years ago, three of her students chose the penny.
Christine Knobel, Nicole Tan and Darin Reyes spent a semester analyzing the information they could find to make an assessment of the penny's ecological footprint. Their conclusion was the true cost of making a penny adds up to much more than 1.43 cents.
The Mint itself has tried to find out if making coins out of different metals might make them cheaper to produce, but it concluded, that for the penny, "there are no alternative metal compositions that reduce the manufacturing unit cost of the penny below its face value," according to a 2014 report to Congress.
Each Mint facility conducts monthly environmental compliance audits and aims to reduce direct emissions by 33 percent by 2020. The Denver Mint is already 100 percent wind-powered and the stamping presses now have a sleep mode to reduce power consumption when not in use.
Between weak economic demand and environmental impacts, nearly a dozen countries have concluded that the penny's not worth it. Canada abolished its penny in 2012, joining countries including Australia, Brazil, Finland, New Zealand, Norway and Israel.
The Mint has made pennies of 98.5 percent zinc and 2.5 percent copper since 1982.
Jarden Zinc Products, the sole company that produces penny blanks for the U.S. Mint to stamp into finished coins, declined to comment on any aspect of its production or the sourcing of their metal other than to say it is "all completely recyclable," according to Mark Blizard, the company's vice president of coinage sales. A company product sheet states the zinc is "mined, processed and formed in America," describing the zinc as coming from Tennessee mines owned and managed by Nyrstar. Yet Nyrstar company representatives assert that Jarden is not one of their clients and has no direct connection with the penny-making process.
Adding to the confusion, the Mint itself reported in 2014 that the zinc comes from Canada.
Pennies made up 56 percent of the Mint's production run last year.
In 2014, the Mint produced 8.15 billion one-cent coins. That's 22,450 tons of pennies, which equates to 21,888 tons of zinc and 562 tons of copper. The same year, 651 tons of copper was used to make "consumer products." That means 86 percent of the copper destined for consumer products was used just for pennies. For zinc, the percentage is smaller, 2 percent of the 1.1 million tons of refined zinc consumed in 2014.
Getting all that ore out of the ground is costly, in terms of carbon dioxide emissions, pollutants and power consumed. A 2009 analysis found that Western copper mines use 35.7 gigajoules of energy per ton of copper produced. Zinc and lead mines are fairly more efficient, using 6.6 to 6.8 gigajoules of energy per ton.
Copper mines, located mostly in Arizona, tend to be of the open-pit variety, which allows more substances to be released. Zinc mines can be open or closed.
Here's what zinc must go through before it is pure enough to be lacquered with copper and punched into a coin. Mining involves blasting and chipping zinc-containing sphalerite ores away from the surrounding limestone, then crushing and processing the ores in chemical baths that separate the zinc from other minerals. At the smelter, raw zinc is roasted to remove sulfides, then sent through a leaching and purification process.
The main byproducts of this process include sulfuric acid and sulfur dioxide. Mercury is another impurity removed during this process.
After being rolled out to the proper thickness, coins are stamped out into circles called planchets, which are polished and then electroplated with pure copper. Shipped to the U.S. Mint in either Denver or Philadelphia, die presses stamp Abraham Lincoln's likeness and a federal shield onto either side of the coin with 35 tons of force. After inspection, coins are trucked to one of 12 Federal Reserve banks.
Despite the fact that the United States recycled 71.8 million tons of metal in 2013, not a single penny made today is recycled, at least by the Mint. Nor are any coins at the moment.
Pennies have an estimated 25-year life span, but demand from year to year varies. People do try to "recycle" them. The company known for its green-and-white coin-collecting kiosks, Coinstar, processed more than 18.5 billion pennies in 2015, which are all eventually deposited with banks, said Susan Johnston, a representative of the company.
So if the penny can't be made greener, why not get rid of it entirely?
Anti-pennyists have trotted out arguments advocating for the penny's elimination. Former Arizona congressman Jim Kolbe introduced three bills from 1989 to 2006 to try and get the government to ditch its smallest denomination.
But, plenty of people are fine with the penny. For some, its chief value is sentimental. Others worry that customers will suffer if prices get rounded up rather than down.
There's one group that really wants to keep the penny around. Jarden Zinc Products. Their current contract with the Mint is valued at $425 million, according to Mint spokesman Michael White.
For Knobel, the answer seems clear. Economically as well as environmentally, it makes sense to get rid of the penny.
"After doing the research, it became clear that the penny isn't needed," she said. "If the Mint is trying to reduce energy, why not reduce it by a whole coin?"