In the wilderness north of Great Slave Lake, in Canada’s Northwest Territories, mining companies are eyeing a potential treasure trove of critical minerals as demand for lithium, nickel, graphite, and copper has risen sharply to meet the needs of the burgeoning electric vehicle and solar power industries.

The cost of mining in this and many other roadless parts of northern Canada used to be prohibitive. That changed last December, when the Canadian government announced its highly anticipated Critical Minerals Strategy, which offers mining companies generous tax breaks, $3 billion in additional funding incentives, and a promise to fast-track the federal environmental impact review process.

While the strategy is being touted as a way of helping the world transition to a post-carbon economy, some environmentalists fear that it will result in drained wetlands, diverted streams, and the disturbance of carbon-rich peatlands. Over the past three decades, the mining industry has walked away from these and many other environmental liabilities, leaving Canadian taxpayers with cleanup bills amounting to more than $10 billion.

“In this transition to renewables, two clear storylines have emerged,” says Teresa Kramarz, a professor and co-director of the Environmental Governance Lab at the University of Toronto and co-chair of the United Nations Development Programme’s Advisory Group on Energy Governance. The first, she says, is the political urgency to rapidly decarbonize, while the second is the enormous business opportunity presented by mining for critical minerals needed for a clean energy revolution.

The blending of these storylines concerns Kramarz, as well as many other scientists and environmentalists, because the overall benefits of mining might not outweigh its costs to biodiversity and to Indigenous people who live in mineral-rich regions.

Nor is there any guarantee that reserves of minerals like lithium are large and accessible enough for Canada to compete with reserves in South America and China, which are much larger and are subject to less environmental oversight.

“The Critical Minerals Strategy is one important step and welcomed, given the need for Canada to strengthen supply chains to support the energy transition from fossil fuels to renewable energy sources,” says Justina Ray, senior scientist and president of the Wildlife Conservation Society Canada. “But the strategy doesn’t fully appreciate the global [ecological] significance of mining regions such as the Hudson Bay Lowlands, the second largest peatlands in the world.” While peatlands account for only 3 percent of the Earth’s land, they store approximately 30 percent of the planet’s soil carbon. A quarter of the world’s peatlands are found in Canada. What’s needed, says Ray, “is a regional assessment led by federal, provincial, and Indigenous leaders to determine whether the trade-offs are worth the cost to biodiversity.”

Most of the critical minerals reserves are located in remote regions of the Northwest Territories, Nunavut, and northern Quebec, and in the Hudson Bay Lowlands of northern Manitoba, Ontario, and western Quebec.

The mine that Fortune Minerals is exploring in the 3,700-square-mile mineral region north of Great Slave Lake lies within the migratory path of the Bathurst caribou herd, whose numbers have crashed from a high of nearly 470,000 in the 1980s to 6,240 today, due to a number of factors including mining disturbance, overhunting, and climate change.

In the so-called Ring of Fire region, in the 124,000-square-mile Hudson Bay and James Bay Lowlands, mining activity could accelerate the thawing of permafrost that stores nearly 35 gigatons of carbon and degrade the habitat of caribou and the nesting grounds of millions of birds. The Lowlands, according to Jeff Wells, vice president of boreal conservation for the National Audubon Society, are “astonishingly important.” No other place on the planet has as many red knots, semipalmated sandpipers, dunlins, and other nesting shorebird species. The Lowlands also are possibly the most important refuge for woodland caribou, which are now functionally extinct in the United States and disappearing quickly across Canada.

Politically, the Critical Minerals Strategy is a win-win for Prime Minister Justin Trudeau’s Liberal government. It speaks to the Conservative Party’s demand for more mining jobs and regional economic development while addressing the left-wing New Democratic Party’s demand for climate action.

If the past history of mining in northern Canada says anything about the future, there are plenty of reasons to be concerned, especially with the Ontario, Manitoba, and Northwest Territories governments signaling their desire to speed up mining for critical minerals.

Just a few dozen miles from Fortune’s play in the Northwest Territories, the Colomac gold mine’s tailings ponds once overflowed with cyanide and ammonia, triggering a mining inspector to complain of burning eyes and a sore throat just minutes after arriving at the site. After low gold prices finally shut the mine in 1997, Colomac’s $1.5 million security deposit, posted to cover environmental liabilities, didn’t come close to covering the $53 million cleanup that was performed at taxpayer expense.

The final cost of the remediation at Colomac, whose initial phase included construction of a five-mile fence to keep caribou out of contaminated areas, is dwarfed by the resources that continue to be poured into two ongoing remediations.

The Faro zinc mine, which operated in the central Yukon between 1968 and 1998, was once the largest open-pit lead-zinc mine in the world. Today, it is one of the most complex abandoned-mine remediation projects in the country, if not the world. Its 77 million tons of tailings and 353 million tons of waste rock contain high levels of heavy metals, which authorities fear could potentially leach into the mountainous headwaters of many fish-bearing streams. The remediation, which began in the early 2000s, is expected to take between 10 and 15 years at an estimated cost of $500 million or more.