Understanding the Earth System through Numerical Modeling: Crossing the Disciplinary Frontiers (Invited Presentation)

Mathematical modeling based on fundamental scientific principles has been the core analytical tool for the understanding and prediction of changes in the Earth's climate system due to natural and human-influenced drivers e.g., aerosols from volcanic eruptions, changes in solar irradiance, greenhouse gases, and pollution aerosols. Beginning about the middle of the last century, and with advances in computing over the decades, numerical modeling investigations have expanded from the very first examination of the changes in the planetary radiation balance to incorporating systematically more and more of the factors affecting climate and examining the resulting influences. Steady advances in theoretical basis and modeling have led to the development and coupling of the atmosphere to land, ocean, and ice components, permitting a more comprehensive assessment of the impacts. With inclusion in more recent decades of atmospheric chemistry, biogeochemical cycles, and ecosystem science, models can increasingly capture more of the “Earth System” response to the drivers. The evolution in modeling, combined with advances in observations, has enabled increasingly challenging scientific questions about environmental changes to be better addressed, including the what, why, and how are the changes manifest in different regions, and what lies ahead in the future. In this presentation, we examine the evolution in the modeling of the Earth System response to the drivers, the current state of understanding including the uncertainties, and future projections and predictions. We also explore how the growth in knowledge of the intersections among the various disciplines constituting the Earth System has, through observations and modeling, yielded inputs into decision-making relevant for vulnerabilities, mitigation and adaptation.