A worldwide increase in large-scale land acquisitions over the past decade has been described as a global land rush for access to natural resources. ‘Land grabbing’ is a dynamic of land-use change that can enable especially rapid environmental transformations across vast spatial scales. New scholarship is beginning to address these land deals in terms of their implications for social and political systems, but exploitative land uses also leave legacies of change in physical landscapes. Historical precedents from around the world, including various examples of frontier expansion, reflect the kinds of environmental responses that modern land grabbing could induce. Insights into land grabbing as a mechanism of abrupt, large-scale transitions in human–environmental systems is a research opportunity and a pressing grand challenge for Earth-surface science.