The working paper, to be released Thursday, warns that current piecemeal assessment tools are inadequate for the vast, unspoiled but mineral-rich region known as the Ring of Fire.
The issue has taken on new significance with the province's newly re-elected Liberal government promising quick action on development in the region.
"Ontario will have only one chance to get it right in the Far North," the paper states.
"We simply will not be able to circle back and undo poorly considered decisions about development, infrastructure or ecological and social tradeoffs once plans are approved and shovels are in the ground."
The paper by the Wildlife Conservation Society Canada and Ecojustice Canada advocates a holistic approach to development planning.
From the outset, the authors state, the process must involve government, First Nations, industry and local communities and come up with an overall, long-term vision for the region.
Such an approach — dubbed regional strategic environmental assessment — would result in a "made in the North" process and plan to address development and conservation across the region, according to co-authors, Cheryl Chetkiewicz, a conservation scientist with the Wildlife Conservation Society, and Anastasia Lintner, a lawyer and economist with Ecojustice.
The Far North, including the Ring of Fire, which First Nations refer to as Wawangajing, is considered globally unique. The 450,000-square-kilometre area is home to one of the world's last intact ecosystems and an important storehouse of carbon. It is also rich in minerals such as chromite and nickel, worth by some estimates in the tens of billions of dollars.
Aside from about 24,000 aboriginals in 34 remote communities, the area is home to at-risk species such as caribou, wolverine and lake sturgeon. It provides refuge to nesting songbirds and includes some of the world's largest peatlands and wetlands.
It's also the world's largest continuous area of unblemished boreal forest.
"This is not a place that can be 'offset' or restored if it is damaged or destroyed by poorly planned development," the paper states.
Development — whether mining, forestry or hydroelectric — will require new roads, railways, power lines, construction sites and housing.
However, current assessment models — largely based on the needs of southern Ontario — tend to focus on individual projects rather than on the cumulative effects of multiple developments over time, the authors write.
"This is a critical flaw given the importance of maintaining the region-wide ecological and cultural integrity across the Far North," they say.
Ontario's environmental commissioner along with the province's Far North advisory panel and advisory council have all pressed for an integrated approach.
Failure to engage in such a process could result in frustrating legal battles. It could also lead to negative long-term social impacts on First Nations from what is typically a boom and bust economy, Chetkiewicz said in an interview from Thunder Bay, Ont.
"None of those kinds of questions will come out in an environmental assessment process and none of them are being addressed in the land use planning process," Chetkiewicz said.
The paper makes several recommendations, including taking the "big picture" into account before development starts.
It also urges extensive monitoring to assess ecological impacts; ensuring development considers long-term sustainability; and consolidation of various assessment laws into a single integrated framework.
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