Climate-mine life cycle interactions for northern Canadian regions

Abstract

This study quantifies the impacts of climate change on the mine life cycle (development, operation and closure phases) of 30 mines located in the northern regions of Canada. To this end, climate projections based on a five-member transient climate change simulation ensemble, performed using a state-of-the art regional climate model, spanning the 1991–2050 period, corresponding to the Representative Concentration Pathway 8.5 emission scenario are used. A reanalysis-driven simulation for the 1991–2010 period compared against available observations confirm suitability of the model for application in climate change simulations. Assessment of projected changes to mine-relevant climate variables that are important from structural integrity and operation perspectives reveal potential vulnerabilities and opportunities. Active layer thickness increases in the 0.3–2 m range in permafrost regions, coupled with increases in flood probability, as reflected in snow-melt rate increases in the 0.14–6.77% range and increases in the 100-year return levels of daily maximum rainfall in the 5–50% range, suggest potential impacts on the structural integrity of mine infrastructure, such as slope instability and foundation settlement of tailings dams, and supporting infrastructure such as ice/all-season roads. Increases in soil moisture, projected in the 0–11% range, at a few mines, suggest potential impacts on material handling systems, such as increases in the traction factor of the muck-haul and tire rolling resistance, that can lead to low productivity. Projected increases to wind speeds in the 5–10% range for the northernmost regions suggest potential impacts on the tailings management facility in terms of increases in tailings resuspension. Overall, this study identified northernmost and northeastern mines to be more vulnerable, with air/soil temperature, precipitation and wind speed being the most influential climate variables. This systematic study, for the first time, has identified potential vulnerabilities of northern Canadian mines, which can inform future high-resolution climate modelling and detailed at-site climate-mine interaction studies that is required for climate-change adaptation related decision-making.