Authors: F. Stuart Chapin III and Sandra Díaz
Scientists have known for more than a century about potential human impacts on climate (1). In the last 30 y, estimates of these impacts have been confirmed and refined through increasingly precise climate assessments (2). Other global-scale human impacts, including land use change, overharvesting, air and water pollution, and increased disease risk from antibiotic resistance, have risen to critical levels, seriously jeopardizing the prospects that future generations can thrive (3⇓–5). Earth has entered a stage characterized by human domination of critical Earth system processes (6⇓–8). Although the basic trajectories of these changes are well known, many of the likely consequences are shrouded in uncertainty because of poorly understood interactions among these drivers of change and therefore their effects on ecosystems and societies.