Climate considerations in tailings management have been highlighted by the publication of the Global Industry Standard on Tailings Management (GISTM) in 2020. The standard states that the knowledge base related to tailings facilities should ‘capture uncertainties due to climate change’.
One of the parameters included in climate change analysis is precipitation and precipitation trends. Short-duration, high-intensity precipitation events have become more frequent across the globe.
SRK has been developing site-specific climate estimations based on general circulation models (GCMs) that are normally used for weather forecasting and projecting climate change. Data are derived from the NASA Earth Exchange Global Daily Downscaled Projections dataset comprising global climate scenarios from 35 GCMs.
Many future climate change implications will depend on actions of the global community. For this reason, the Intergovernmental Panel on Climate Change (IPCC) has established shared socioeconomic pathways (SSPs) which correspond to different hypothetical geopolitical responses. For example, SSP1-1.9 assumes a rapid transition away from fossil fuels, whereas SSP3-7.0 assumes a continuation of the current global emissions trend.
SRK’s product uses state-of-the-art models to assess future changes under two pathways: SSP2-4.5, a mid-case emissions future that assumes climate protection measures being taken by all nations, and SSP5-8.5, a worst-case scenario. The data span the globe with approximately 25 km spatial resolution using historical data from 1950 to 2014 and climate projections from 2015 to 2100. Climate change modelling is conducted through compiling available GCMs and completing an analysis with a purpose-built script using R, a programming language for statistical
computing. The analysis provides the estimated change of different climatic parameters for a specific location.
SRK’s R script captures daily climate parameters until 2100, and further review is done for mine-specific time periods. For example, the first assessment period covers the period from 2020 to 2049, representing the operational mine phase. Climate changes during this period are most likely to influence operational design and management. The second assessment period in the table represents the period from 2070 to 2099, which predicts the climate that may influence closure design and post-closure monitoring.
One key output of the analyses is statistical representation of all the GCMs for defined time periods, including the median value and the possible range of change for various parameters. The results can also graphically represent seasonality to understand monthly projected changes by decade (Figure 1). This can inform water balance and mine infrastructure design, which is vital for mine sites that rely on stormwater.
