Drawing on reliable data on land use, consumption, and environmental impacts stretching back to 1961, the IPCC report’s authors make a variety of longitudinal observations. They point out that human use directly affects more than 70 percent of the earth’s ice-free land surface; indirect effects obviously reach the entire globe. The past 58 years have seen significant per capita increases in food production, with overall calories per capita rising by about a third despite the enormous population increase over the same period. In addition, commercial forestry, industrialized mining, and other extractive activities have increased over the period. In total, about a quarter of usable land faces human-induced degradation. These activities have both contributed to climate change and will themselves be affected by climate change. We will focus on these changes over time, looking for historical patterns and reflecting on their implications for continued transformations. We will respond directly to the IPCC’s warning that mitigating climate change’s effects will demand further action.

This roundtable includes seven historians who bring to bear expertise on the histories of land use in all seven continents. We are historians of environment, agriculture, mining, and energy. We will draw on our own work and others’ to discuss how land use changed dramatically over the past century, from the massive conversion to arable to urbanization to the Green Revolution to industrialized mining. Using this pooled knowledge and working collaboratively with the audience, we will discuss policy responses to the IPCC report, international collaboration over the coming decades, and what role historians should play in these urgent debates.