Modified spatial network approach to predict mobilisation emissions from upstream mineral exploration: applications to British Columbia’s critical mineral sector

• First methodology for predicting greenhouse gas emissions from mineral exploration. • Upstream mineral exploration industry classified into six key work activities. • Example greenhouse gas inventory as well as data products for decision-making. Reaching global climate targets and the energy transition will require new sources of critical minerals. Exploration and mining activities generate greenhouse gas (GHG) emissions, but the relative contribution of emissions from all portions of the mining value chain remains poorly understood. Here, we divide the upstream portion of the mining value chain (i.e., mineral exploration) into six activities, representative of most Scope 1 emissions. We present spatial methods to estimate GHG emissions for ground and air transport and apply these methods to constrain emissions of three of the six exploration activities. A ground-transport model is informed by a spatial network analysis finding least-cost paths and fuel economy; whereas the air-transport model is informed by straight-line proximity to start locations and aircraft burn rate. We use these models in two applications. First, producing continuous maps of a single exploration activity with an example of field work mobilisation in British Columbia, Canada (i.e., mobilising a single vehicle) that can be used in a comparative fashion, where emissions of the activity can be compared between any two points in the modelling area. Second, a detailed emissions estimation contrasting two hypothetical drill programs, analogous to a GHG inventory when fuel use is not detailed in exploration reports. The methods and example data products presented here demonstrate how large-scale emissions inventories could be completed for the upstream exploration sector and used to define exploration areas prospective for critical minerals that will generate the lowest amount of GHG emissions.