This is a past event.

Jed O. Kaplan
Environmental Engineering Institute
Ecole Polytechnique Fédérale de Lausanne (EPFL)
Lausanne, Switzerland

How can changes in the terrestrial biosphere amplify changes in the climate system? Biogeophysical changes, including changes in forest structure and surface albedo, and biogeochemical changes such as emissions of greenhouse gases, dust and other aerosols, all feed back to climate by changing the radiative budget of the Earth’s surface and atmosphere. These feedbacks can operate on rapid timescales that are relevant to human activities, and may be triggered by both natural causes and human activities. While humans have often been assumed to act independently of climate and other environmental constraints, the past half-century of scientific research has led to growing awareness of the close relationship between humanity and their environment from the emergence of modern humans to the Industrial Revolution. The major developments in human society during the since the end of the last Ice Age include agriculture, urbanization, written language, and modern civilization, and such developments were all influenced by environmental conditions. Likewise, human activities may have strongly influenced the climate system itself, possibly even to the point of precluding future Ice Ages. While this point is rather contentious, our research shows that both vegetation and soils have very long memories when it comes to the long history of human interaction with global land cover.

Through the interdisciplinary study of the interaction between soils, vegetation and the atmosphere, the ARVE group at the Ecole Polytechnique Fédérale de Lausanne is attempting to answer the question of how a dynamic terrestrial biosphere can amplify ongoing climate change. Using innovative new modeling techniques, we are studying how terrestrial nitrogen cycling responds to abrupt climate change events, how long term soil erosion and degradation could have led to widespread, irreversible changes in land cover and ecology, and how the long history of human land use limits the capacity of the terrestrial biosphere to be a carbon sink in the future. This talk will provide an overview of our ongoing research on these and other topics, and provide a basis for discussion on the future of interdisciplinary earth systems science research.