Potential climate change effects on the geochemical stability of waste and mobility of elements in receiving environments for Canadian metal mines south of 60°N

Increased temperatures and changing amounts of precipitation may alter environments, increasing the challenges faced by mines. This is a paper on topics relevant to metal mine biogeochemical environments, related waste management, element transport, and environment health south of 60° latitude. Mine waste can contain elements of interest (EOI) that may have adverse environmental and biological effects at concentrations that are higher than in undisturbed sites. Elevated concentrations of EOIs are transported by water as solutes and particles. Wind erosion also transports particles, and establishing its contribution and effects is challenging. Dispersal of EOI can be controlled at the source using water covers, geomembranes, geosynthetic clay liners, and covers with capillary barrier effects. Drainage that can be produced over a wide range of pH must be treated to meet environmental requirements. Water treatment can produce sludge that must be stored or processed. The success of these mitigation measures can be observed in the biological health of organisms at the site and vicinity. Processes responsible for EOI dissolution and transport, waste control and water management systems, and the stress experienced by biota near mines are all subject to climate change effects. Understanding and adapting to challenges from a rapidly changing environment will require cooperation between industry, government, mining communities, and scientists. Ideally, adaptation measures should correspond to temperature and precipitation projections, but this information is not always available at the relevant geographic scale. To anticipate emerging risks, it may be necessary to explore a variety of scenarios at lab and field scales, and to implement robust and flexible management techniques.