The Geological Consequences of Global Climate Change

Global climate change has imminent and severe geological consequences that are already becoming apparent across a wide variety of environments, from the cryosphere, to coastal regions, and terrestrial systems. Modern observations and recent historical records show that global change has already resulted in ice-loss with significant retreats in glacial and permafrost regions, measurable sea-level rise and substantial losses in land area and coastal stability, and shifting erosion rates, desertification, and changes in weathering and carbon cycling on land. Geologic records show that similar consequences, and a wide range of others, have resulted during periods of past climate change, and model and proxy data may provide a set of natural experiments for understanding the impacts and extent of modern and future change. However, these archives also suggest that some aspects of modern global change, including rate, fall outside the realm of analogous environmental conditions. Despite this, it is possible to classify and describe important geological consequences of global climate change in each of these systems: (1) cryosphere impacts including glacial isostasy, landscape destabilization, and changes in regional hydrology; (2) coastal systems impacts including sea level rise, coastal erosion, and flooding events; and (3) terrestrial impacts including system-clearing events, desertification, and changes in the carbon cycle. Understanding and describing geological consequences of global climate change and their interactions and causes is crucial for planning adaptation and mitigation strategies for continued future change, and for limiting the impact of these consequences on global environments, key ecosystems, and human infrastructure.