Land clearing for nickel mines is causing a more severe threat to the climate than initially thought, a study led by a University of Queensland researcher has found.

Dr. Evelyn Mervine from UQ’s School of the Environment analyzed data from 481 international nickel mine sites and undeveloped deposits and found the land footprint of nickel mining could be four to 500 times greater than previously reported.

The research paper is published in Nature Communications.

“Nickel is commonly used in renewable energy infrastructure, such as in batteries and corrosion-resistant steel, and demand is expected to double by 2050 to support low-carbon technologies,” Dr. Mervine said.

“However, the biomass carbon emissions from vegetation clearing for nickel mines are almost always overlooked in carbon accounting, sustainability reports, and sourcing decisions.

“Nickel is one of the easiest metals to recycle, and according to the Nickel Institute, about 68% is already recycled.

“But even if we increase nickel recycling to 100%, we will still need to produce more nickel for renewable energy technologies, such as electric cars and solar, wind, and geothermal power plants.”

With nickel mining currently unavoidable, Dr. Mervine said the research highlighted a need for mining companies to avoid developing new mines in areas where there is “irrecoverable carbon”—carbon stored in ecosystems such as old-growth rainforests and mangroves, which once cut down can never be restored back to their original biomass densities.

Dr. Mervine said biomass carbon emissions were highly variable depending on the location of the nickel mine.

“At some nickel mines the biomass carbon emissions are almost zero while emissions at others are significant—for example, compared to the emissions from diesel used by mining vehicles or the coal burned in a nickel smelter,” she said.

“Regardless of their severity, these emissions need to be reported.

“Companies should prioritize the development and expansion of mine sites in areas that have low biomass densities, such as in deserts, rather than in rainforests, while, of course, being mindful of environmental impacts beyond carbon.”

Senior Author Adjunct Associate Professor Laura Sonter said mining companies should take multiple steps to minimize land transformation while meeting the growing demand for nickel.

“It’s key that all mine sites begin to survey, track, and report their land use footprints and the associated carbon emissions from deforestation,” she said.

“This will enable companies, buyers, governments, and other stakeholders to make informed decisions about how best to source the nickel required for low-carbon technologies.”

Dr. Mervine completed this research as part of her Master of Science at the University of Edinburgh.