Global demand for steel drives extensive land-use change in Brazil’s Iron Quadrangle

Global demand for minerals is often considered an insignificant driver of land-use change because mines are small. We (1) investigated evidence supporting a link between global demand for steel and land-use change in Brazil's Iron Quadrangle, and (2) quantified the extent of land-use change and associated impacts on native vegetation. Historic land-use change was quantified using Landsat TM, relationships between demand for steel and land-use change were investigated using a simple linear model, and future scenarios were simulated using a calibrated land-use change model. Results support our hypothesis that global demand for steel drives extensive land-use change in the Iron Quadrangle, where increased steel production was correlated with increased iron ore production and mine expansion, and with increased charcoal production and plantation expansion. The direct impacts of mining on native vegetation were disproportionate to their relatively small spatial extent, while direct impacts of plantations were spatially extensive, as were their impacts on surrounding native vegetation. Additionally, evidence of two indirect impacts emerged during 1990–2010. Plantation expansion decreased native forest regrowth, while competition for land between mining companies and urban developers increased deforestation pressures. In combination, global demand for steel affected the majority of land in the Iron Quadrangle; however, many impacts were poorly captured by current land management approaches. Similar processes may operate in other mining regions, where global demand for minerals drives production of multiple resources (non-renewable and renewable) and thus extensive land-use change.

Read the full paper: Sonter, Barrett, Soares-Filho & Moran (2014), "Global demand for steel drives extensive land-use change in Brazil’s Iron Quadrangle". Global Environmental Change 26, 63-72. DOI: 10.1016/j.gloenvcha.2014.03.014