Critical Zone Science and Global Societal Challenges

Abstract:

Earth's Critical Zone (CZ) is the thin outer veneer of our planet from the top of the tree canopy to the bottom of our drinking water aquifers that supports almost all human activity. Despite its fundamental importance to terrestrial life, understanding of the operation of the coupled geologic, hydrologic, topographic, and biotic CZ processes across time and space is far from complete. These interactions are complex and they establish a mechanistic ‘chain of impact’ that transmits the effects of environmental change throughout the CZ. Characterization of these processes is made more urgent by the fact that globally, the CZ is experiencing ever-increasing pressure from growth in human population and wealth. Within the next four decades, demand for food and fuel is expected to double along with a more than 50% increase in demand for clean water. Understanding, predicting and managing intensification of land use and associated economic services, while mitigating and adapting to rapid climate change, is now one of the most pressing societal challenges of the 21st century. In this talk we summarize the profound global societal impacts to the Earth’s near surface arising from exponential human population growth, increasing affluence, and technological advance, to provide context for discussions on constructing an array of CZ observatories to both characterize fundamental critical zone processes and forecast the effects of planetary change. We will suggest goals and options relevant to planning for a future international array of CZ observatories and a research agenda that matches the urgency of the projected resource demands and environmental pressures of the coming four decades.