Myth Busting: Four Myths about PolyMet, Twin Metals and the Green Economy

Advocacy By Pete Marshall

Many who love the Boundary Waters and Lake Superior, who oppose copper-sulfide mining in favor of a clean-water future, are troubled by the fact that as a society, we rely on the metals Twin Metals and PolyMet seek to extract. Copper and nickel are vital to a 21st century lifestyle. In particular, these metals are needed for windmills, electric cars, and solar panels. They are essential to a green energy future. This has become a favorite argument from the mining companies and their allies. Ironically, many who make this argument deny climate change.

Though this may be a disingenuous stance, it does need to be addressed.

First, it’s important to acknowledge that copper and nickel are a necessary part of the United States building a green future. However, the urgent need for these metals is grossly overstated.

What’s more, getting these metals through traditional mining methods is an expensive, dirty, inefficient and unnecessary way to extract these metals. Looking at the data, we decided to dispel four persistent myths about the green economy and copper-sulfide mining in Minnesota.

Watch a presentation and discussion of this topic


This is the big one we hear over and over again.

Ironically, recent research published by Nature — perhaps the most prestigious group of science journals in the world — estimates that mining for primary metal and mineral production accounts for approximately 10% of the total global energy-related greenhouse gas emissions. Because the remaining copper deposits around the world are so poor, copper mining has become increasingly fuel intensive. From 2001 to 2017 in Chile — the world’s largest copper producer — the electricity consumption per unit of mined copper increased by 32%.

In another blog, we discussed a recent study that looked at the impacts PolyMet and Twin Metals would have on the climate. According to the study, greenhouse gas emissions from both mines would spew upwards of 1.9 million tons of CO2 into the atmosphere each year, equivalent to 372,000 passenger cars.

In addition, these mines would destroy thousands of acres of wetlands, which serve as a critical means of carbon sequestration and are one of the most effective carbon sinks on the planet.

According to Twin Metals’ Mine Plan of Operation, the company would destroy 912.4 acres of peatland, which, based on figures from Minnesota DNR, would release almost 2.5 million metric tons of CO2.

PolyMet, which would involve the largest permitted destruction of wetlands in Minnesota’s history, would wipe out an additional 1,000 acres of wetlands, two thirds of which are peatland — a critical carbon sink. From wetland destruction alone, Twin Metals and PolyMet would release around 4.3 million metric tons of CO2, more than the yearly greenhouse gas emissions from a coal plant.

Photo: Bobby Marko


There is an unchecked argument that goes something like this: Because we use more computers and are building more windmills (both of which require copper) we are therefore using more copper and hence, need Twin Metals and PolyMet to open in order to meet the demand.

Not to mention the population is growing. So, of course we need more copper.

In actuality, U.S. copper consumption has decreased dramatically over the past several decades. According to the U.S. Geological Survey, the United States consumed 3,100,000 metric tons of copper in 2000 and consumed 1,600,000 metric tons in 2020. Despite a growing population and the rise of green technology, we saw an overall decrease of 48% in copper consumption.

Graph showing declining U.S. copper consumption


Recently, pro-mining allies have changed the story by asserting that we need PolyMet and Twin Metals in order to get critical minerals such as platinum, palladium and cobalt. These minerals exist in these deposits, but they exist in trace amounts.

For example, PolyMet estimates that their ore body contains a mere 76 parts per billion of platinum. That’s 0.0000076%. It would take over 13 million pounds of ore to process one pound of platinum.

As for cobalt, the critical mineral that is most abundant in these deposits, it exists in far less amounts than in actual cobalt mines. Twin Metals’ deposit, which has a far higher grade of cobalt than PolyMet, only contains 110 parts per million — or 0.011% — of cobalt. Compare this to the proposed Jervois Cobalt mine in Idaho, which has a grade of 0.55% of cobalt — 50 times the concentration.

The argument that these mines will be an important source of critical minerals is a red herring, an attempt to change the subject and get around the fact that we are not in desperate need of copper, the primary metal these mines would extract.

On this note, it’s worth mentioning that nickel, the secondary metal in both deposits, would hardly be used in the green economy. Though it may be an essential part of the batteries that charge electric vehicles, only 5% of mined nickel goes to batteries, according to the Nickel Institute.


The answer is simple: Recycling.

Because the remaining copper and nickel deposits around the world are such low grades, these metals are becoming more expensive to extract and causing more environmental damage in the process. This underscores how important it is to recycle these metals. Currently, the United States gets only 38% of its copper from recycling. If the U.S. procured just 50% of its copper from recycling — similar the current rate the European Union — this would produce more copper each year than would be extracted by five Twin Metals or almost ten PolyMet mines.

Scrap copper

Further, researchers estimate that recycling and extracting copper and other metals from e-waste would be 13 times cheaper than opening a new mine. It would also require 85% less energy than extracting it from ore in the earth. While we need to invest more into recycling, it’s important to note that the current state of electronics recycling is far from perfect.

Electronics are often shipped overseas, to developing countries where hazardous materials and unsafe conditions expose people to toxins and poisons in e-waste. This is a major environmental justice concern. Fortunately, significant attention is being directed to this problem and organizations such as Basel Action Network are working to implement safe and effective recycling practices that benefit people and the environment.


Pro-copper-sulfide mining interests advance these four myths in a contrived effort to portray themselves as concerned about the well-being of our planet. However, an objective consideration of climate change, the demand for copper, the trace amounts of other minerals in northeastern Minnesota’s ore deposits, and the untapped potential of metal recycling, reveal that these concerns are little more than a cynical attempt to deceive the public.

Pete Marshall is the communications director for Friends of the Boundary Waters Wilderness.

Comments (1)

David Meier

2 years ago

Hello it's Dave and this is a test

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