Topic 5. Climate versus anthropogenic forcing of Late Holocene environmental change affecting Indonesian marine, coastal, and terrestrial ecosystems (CAFINDO)

A detailed analysis of past environmental variability in the Indonesian region related to climate change is vital to reduce uncertainties about future regional developments. Over historical times the effects of natural climate on environmental variability have been "modified" by an increasing impact of human activities. To assess this human contribution to environmental change, high-resolution records of natural climate variability as well as of environmental variability in regions having been subject to various degrees of anthropogenic forcing are needed. Thus, discerning past natural climate forcing and the impacts of agricultural activities, forestry and pollution (etc.) on environmental variability in Indonesia could support a better estimation of future environmental variability in times of accelerating global change.
Consequently, this project aims to study both, the natural environmental variability and the effects of increasing land-use (and other factors) by humans during the last 4,000 years. By outlining the interplay between natural variability and anthropogenic forcing, this project will contribute to develop strategies for the governance and management of Indonesian marine, coastal, and terrestrial ecosystems.

For the proposed project surface sediments from the Java Sea collected by the Indonesian proponents will be utilized to assess the present-day state of marine sedimentary proxies indicative for various terrestrial and marine environmental variables. Based on this "calibration" sediments accumulating offshore two rivers from Kalimantan that are largely unbiased by human interference (Pembuang and Jelai), and two rivers from Java that are strongly affected by land-use and irrigation (Bengawan Solo and Citarum) will be analyzed in order to untangle natural and anthropogenic induced environmental changes during the past 4,000 years.