A methodological approach for assessing cross-border supply chain exposure to climate change impacts on crop production and transport

In an interconnected world, countries are exposed to climate change impacts beyond their borders, transmitted through international linkages such as trade. Despite growing attention to cross-border climate change impacts, the recognition of these types of impacts in policy responses, adaptation planning and risk assessments is still limited. In part, this is due to an absence of methodologies for quantifying exposure to cross-border climate impacts. In this paper, we propose a methodological approach to assess crop supply chain exposure to cross-border climate change impacts. We build on previous work by 1) proposing a subnational analysis to account for the spatial heterogeneity of different supply chains, 2) including climate change impacts both on crop production and crop transport, and 3) considering interannual variability, alongside long-term climatic changes, to capture potential acute supply chain disruption. We illustrate our methodological approach with a case study of Brazil soy exports, comparing two different importers’ supply chains, and focusing on climate change impacts on crop yields and drought affecting waterways. Our methodology highlights how different importers have different levels of exposure to climate impacts, depending on the areas they source soy from and the transport modes and routes used. Whilst increasing data on supply chains allows us an ever more detailed understanding of supply chain exposure to cross-border climate change impacts, data limitations are still a major barrier to accurate projections, and we discuss improvements for future work.