Holocene environmental catastrophes in South America: From the lowlands to the Andes

摘要

Concern over future recurrences of recent environmental catastrophes, such as the Indian Ocean tsunami or the devastating hurricane season of 2005, are everyday discussions not only for scientists but also for people overall the globe. In addition, global-warming induced changes in mean climate states and in the frequency and magnitude of extreme climatic events, increasing human vulnerability to environmental catastrophes. For geoscien-tists, environmental catastrophes include short-time (tsunami, volcanic eruption, earthquake) or long and slow-evolving events lasting years or even decades (persistent floods or droughts) that produce considerable and extended effects on civilizations and natural systems. A major hindrance in appreciating the full range of environmental changes—especially extreme events—is the general paucity of long-term instrumental records, particularly in southern latitudes. Consequently, high-resolution climate reconstructions beyond these records become critical to understand natural climate variability and, therefore, to unveil the mechanisms behind abrupt and unpredicted reactions of the Earth system. Only then it does it become possible to better prepare for the future (Leroy, 2006, this volume).