The global land surface covers approximately 150 million square kilometers—about 30 percent of the Earth’s surface—and humans occupy or otherwise use roughly 80 percent of the land surface including the 40 percent converted to agriculture. The global population reached 7 billion in 2011 and is projected to increase to 9 billion by 2050. To feed and shelter the planet’s growing population, extensive and intensive land use has been required, but the environmental degradation caused by these requisite activities is diminishing the planet’s capacity to sustain needed food and fiber production and fresh water supply. Foley et al. (2005) states “There is an increasing need for decision-making and policy actions across multiple geographic scales…. The very nature of the issue requires it. Land use occurs in local places, with real-world social and economic benefits, while potentially causing ecological degradation across local, regional, and global scales.”
Land imaging from moderate-resolution Earth-observing satellites, such as Landsat, offer the critical and irreplaceable capability to observe land use and land use change across those scales. Landsat’s space-based land imaging is essential because it provides repetitive and synoptic observations of the Earth otherwise unavailable to researchers and managers who work across wide geographical areas and applications. Landsat data informs good decisions in many disciplines, especially: human health, agriculture, climate, energy, fire, natural disasters, urban growth, water management, ecosystems and biodiversity, and forest management.
