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May 26, 2022

Real climate solutions protect peatlands

Coniferous bog
A coniferous bog in Minnesota. Peatlands can be classified by their water source: bogs are filled by rainwater, while fens are fed by groundwater.

 

May 26, 2022, Abby Rogerson, Northeastern Minnesota Program Associate, MCEA Duluth Office

As decarbonization goes mainstream, mining companies are hopping on the bandwagon and increasingly branding their products as critical for the green economy. While demand for these so-called “critical minerals” is projected to increase, serious questions about the need for new raw materials and mining’s role in the clean energy transition remain. Despite the unknowns, it’s clear that we cannot simply mine our way out of the complex and multi-faceted problem of climate change.

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Above the bedrock and mineral deposits of northern Minnesota lies a blanket of soggy, ancient, carbon-rich soil. These boggy expanses are called peatlands. As we learn more about their unparalleled ability to sequester carbon, it’s becoming increasingly clear that protecting them is critical to avoiding the worst impacts of climate change.

Peatland is a type of wetland that is saturated with water year-round and typically found in cooler climates. In ecosystems like forests and prairies, when a plant dies, the carbon locked in the plant body interacts with oxygen, and the carbon is released back into the atmosphere. But in low-oxygen peatlands, dead plant matter is submerged by water, which prevents it from reacting with oxygen and fully decomposing. Instead, dead plants accumulate and become a type of carbon-rich soil called peat. 

Minnesota’s peatlands have been forming since the glaciers receded over 5,000 years ago, and in some areas the peaty soil is 10 meters thick. Though peatlands are rare, covering just 3% of the Earth’s surface, they are the world’s largest terrestrial carbon store, according to the International Union for the Conservation of Nature. Minnesota is home to more peatlands than any other state besides Alaska, making our state a carbon sequestration powerhouse. 

 

AN MVP OF CARBON SEQUESTRATION

 

Minnesota’s peatlands store over 4 billion metric tons (Mt) of carbon. In 2018, Minnesota emitted a total of 161 million Mt of greenhouse gas. That means the carbon stored in peatlands is equal to about 27 years worth of annual statewide emissions. Despite peatlands’ outsized importance to preserving a livable climate, they’re not typically revered in the same way as other charismatic ecosystems.

Deforestation, especially in places like old-growth rainforests, gets a lot of attention in the climate context. Consider if a copper-nickel mine proposed to clear a swath of old-growth forest in Washington State’s Olympic National Park. Even if the mining company marketed itself as essential for metals used in electric vehicles and wind turbines, the idea that we need to chop down rainforest in order to address climate change would likely be rejected. But the role of Minnesota’s peatlands in sequestering carbon is actually far more dramatic. Olympic National Park stores about 190 million Mt of carbon, about 5% of the carbon stored in Minnesota’s peatlands. Why does it make sense to dig up peatlands when a rainforest would likely be protected from such treatment? The answer is: it doesn’t.

 

PEAT, A CARBON SINK AND SOURCE

 

Intact peatlands lock carbon in a solid soil form, but when drained, all that carbon is released as greenhouse gas. Because peatlands are so carbon-dense, they’re considered a “climatic tipping point,” meaning their destruction would rapidly accelerate climate change. 

Peat disturbance is a major problem in Minnesota, as evidenced in an alarming report by the Minnesota Pollution Control Agency that listed drained peatlands as the state’s fourth largest source of greenhouse gas. While restoration is needed to halt emissions from drained peatlands, the difficulty and cost of that approach makes preservation of intact peatlands the most efficient management tactic. 

Undisturbed peatlands stretch across northern Minnesota, but they face threats as well, particularly from proposed sulfide mines. For example, if built, PolyMet would destroy hundreds of acres of high quality coniferous bog, a type of rainwater-fed peatland, and could drain thousands of additional acres of wetlands, according to its environmental impact statement. A proposed state policy to protect and restore peatlands is one step in the right direction, but activities that impact these valuable landscapes set us two steps back. 

The carbon in peatlands is irrecoverable, meaning if peatlands are destroyed, they will release their stored greenhouse gas, and we will not be able to restore them in time to avoid the climate impact. While the minerals lying below them could hypothetically be used for clean energy technologies in the future, it is certain that destroying peatlands for mining development would have immediate consequences for rising global temperatures. Given the significant risks new mining proposals pose to peatlands, their potential contribution to clean energy must be balanced against the globally significant part we know Minnesota’s peatlands play in curbing the climate crisis.  

 

ADAPT AND MITIGATE, TWO SIDES OF THE CLIMATE COIN

 

Peatlands also help humans and wildlife adapt to climate impacts. For example, the connected expanses of peatland in northern Minnesota allow wildlife to access suitable habitat as climate change alters species’ ranges. Even without the added pressure of climate change, wildlife is vulnerable to habitat fragmentation, which occurs when roads, transmission lines, and other mining facilities are built. When migration corridors are paved over, animals lose the ability to reach the places they use to feed, breed, and spend the winter. Connected habitats become even more important as the climate changes, since species move northward when temperatures in their typical habitat range become too hot. 

Currently, habitat in northern Minnesota is more connected than other parts of the state, but proposed sulfide mines threaten to fragment the region’s connectivity. Large and wide-ranging species living in the Northland, like lynx, moose, and wolves, are particularly sensitive to fragmentation and already must contend with a 50-mile long barrier created by existing mines, towns, and roads. PolyMet’s mine proposal, if built, would cut off one of the few remaining wildlife corridors in the area – a fact that allied groups are not accepting without a fight.

In contrast with new mining, metal recovery infrastructure has a relatively small footprint and can be built in already-developed areas, providing a supply of clean energy metals without putting more pressure on wildlife populations. Above all, environmental stewardship and protection of biodiversity must not be sacrificed in the name of mining for clean energy metals.

Intact wetlands also make people more resilient to climate impacts – for example, by helping communities adapt to the increasingly frequent major rain events we’re already seeing in northeastern Minnesota. Wetlands act as sponges that slow runoff, prevent nutrient pollution, reduce flooding, and prevent infrastructure from becoming overwhelmed by intense rain. As such, wetlands are a common feature of climate-smart land planning. Proposals like PolyMet would destroy, dewater, and pollute thousands of acres of wetlands that regulate water quality and quantity flowing into the St. Louis River. 

As you can see, the significance of peatlands is dramatic and diverse. Peatlands are nature's most effective and powerful carbon sequestration technology, vastly out-storing all the world’s forests and grasslands combined when it comes to greenhouse gas emissions. Further, peatlands are instrumental in helping both people and wildlife adapt to the impacts of a changing climate. Real climate solutions need to protect peatlands, not destroy them. Our ability to achieve a climate-resilient and carbon-neutral Minnesota depends on it.

 

KEY TAKE-AWAYS

 

  1. Protecting Minnesota’s peatlands is one of the most effective tactics to fight climate change, as peat has an unparalleled ability to sequester carbon and can be a major source of greenhouse gas emissions if disturbed.
  2. Large, connected expanses of intact peatlands provide diverse ecosystem services that cannot be replaced and will become more important as the climate changes.
  3. Real clean energy solutions protect peatlands. 

 

MINING THE CLIMATE CRISIS SERIES HOMEPAGE