Interactive effects of solar UV radiation and climate change on the biogeochemical carbon cycling
Event details
| Date | 12.05.2015 |
| Hour | 16:15 › 17:15 |
| Speaker | Dr Barbara Sulzberger, Honorary scientist, EAWAG, Member of United Nations Environment Programme (UNEP) Environmental Effects Assessment Panel (EEAP). |
| Location | |
| Category | Conferences - Seminars |
Abstract:
In my seminar I will present some aspects of the 2014 Assessment Report of the United Nations Environment Programme (UNEP) Environmental Effects Assessment Panel (EEAP). This panel was established by UNEP in 1988 after the Montreal Protocol on Substances that Deplete the Ozone Layer had been signed in 1987. The 2014 Assessment Report includes 7 chapters on the environmental effects of ozone depletion and its interactions with climate change. I am a co-author on Chapter 5 entitled “Effects of stratospheric ozone depletion, solar UV radiation, and climate change on biogeochemical cycling: interactions and feedbacks”.
Interactions between solar UV radiation and climate change are particularly pronounced for carbon cycling, resulting in UV-mediated feedbacks on climate. Possible positive feedbacks discussed in this seminar include: (i) reduced efficiency of the biological pump due to UV-induced bleaching of colored dissolved organic matter (CDOM) in stratified aquatic ecosystems, where CDOM protects phytoplankton from the damaging solar UV-B radiation; (ii) enhanced UV-induced mineralization of photo-reactive dissolved organic matter (DOM) in aquatic ecosystems due to changes in continental runoff and ice melting. The biological pump (CO2 binding in photosynthesis by phytoplankton and export of dead particulate organic matter to the sediment) is the main biological process for CO2 removal by aquatic ecosystems, whereas mineralization of organic matter results in the production and release of CO2.
Terrestrial and aquatic ecosystems are currently net CO2 sinks on a global average, where the CO2 uptake corresponds to ca. 30% and 25% of anthropogenic CO2 emission, respectively. However, the interactive effects of solar UV radiation and climate change on carbon cycling could alter the delicate balance of the global carbon sinks.
Short biography:
Barbara Sulzberger received her diploma in chemistry and her Ph.D. from the University of Bern. Both her Ph.D. and subsequent post-doctoral research at The Royal Institution of Great Britain were related to photochemical solar energy conversion. After an appointment at Ciba-Geigy AG, she joined the Swiss Federal Institute of Aquatic Science and Technology (Eawag) in 1986, then under the direction of Werner Stumm. At Eawag, Barbara Sulzberger headed a group conducing aquatic photochemical research until her retirement in 2007. In 1994 and 1995, she was a guest scientist at the Woods Hole Oceanographic Institution. Her research group at Eawag investigated (i) the effects of solar radiation on the biogeochemical cycling of carbon and of trace metals (iron, copper, manganese) in aquatic systems, (ii) the effects of solar radiation on the chemical composition and bioavailability of dissolved organic matter (DOM), and (iii) the roles of iron in light-induced transformations of organic and inorganic pollutants (atrazine, diuron, EDTA, chromate). She is the co-author or author of over 50 peer-reviewed articles published in international, high-impact journals and of 12 book chapters.
Barbara Sulzberger was a lecturer at ETH Zurich and at the University of Bern. From 2002-2007, she was the editor-in-chief of the journal Aquatic Sciences – Research Across Boundaries. Since 2003 she is a member of the United Nations Environment Programme (UNEP) Environmental Effects Assessment Panel (EEAP).
In my seminar I will present some aspects of the 2014 Assessment Report of the United Nations Environment Programme (UNEP) Environmental Effects Assessment Panel (EEAP). This panel was established by UNEP in 1988 after the Montreal Protocol on Substances that Deplete the Ozone Layer had been signed in 1987. The 2014 Assessment Report includes 7 chapters on the environmental effects of ozone depletion and its interactions with climate change. I am a co-author on Chapter 5 entitled “Effects of stratospheric ozone depletion, solar UV radiation, and climate change on biogeochemical cycling: interactions and feedbacks”.
Interactions between solar UV radiation and climate change are particularly pronounced for carbon cycling, resulting in UV-mediated feedbacks on climate. Possible positive feedbacks discussed in this seminar include: (i) reduced efficiency of the biological pump due to UV-induced bleaching of colored dissolved organic matter (CDOM) in stratified aquatic ecosystems, where CDOM protects phytoplankton from the damaging solar UV-B radiation; (ii) enhanced UV-induced mineralization of photo-reactive dissolved organic matter (DOM) in aquatic ecosystems due to changes in continental runoff and ice melting. The biological pump (CO2 binding in photosynthesis by phytoplankton and export of dead particulate organic matter to the sediment) is the main biological process for CO2 removal by aquatic ecosystems, whereas mineralization of organic matter results in the production and release of CO2.
Terrestrial and aquatic ecosystems are currently net CO2 sinks on a global average, where the CO2 uptake corresponds to ca. 30% and 25% of anthropogenic CO2 emission, respectively. However, the interactive effects of solar UV radiation and climate change on carbon cycling could alter the delicate balance of the global carbon sinks.
Short biography:
Barbara Sulzberger received her diploma in chemistry and her Ph.D. from the University of Bern. Both her Ph.D. and subsequent post-doctoral research at The Royal Institution of Great Britain were related to photochemical solar energy conversion. After an appointment at Ciba-Geigy AG, she joined the Swiss Federal Institute of Aquatic Science and Technology (Eawag) in 1986, then under the direction of Werner Stumm. At Eawag, Barbara Sulzberger headed a group conducing aquatic photochemical research until her retirement in 2007. In 1994 and 1995, she was a guest scientist at the Woods Hole Oceanographic Institution. Her research group at Eawag investigated (i) the effects of solar radiation on the biogeochemical cycling of carbon and of trace metals (iron, copper, manganese) in aquatic systems, (ii) the effects of solar radiation on the chemical composition and bioavailability of dissolved organic matter (DOM), and (iii) the roles of iron in light-induced transformations of organic and inorganic pollutants (atrazine, diuron, EDTA, chromate). She is the co-author or author of over 50 peer-reviewed articles published in international, high-impact journals and of 12 book chapters.
Barbara Sulzberger was a lecturer at ETH Zurich and at the University of Bern. From 2002-2007, she was the editor-in-chief of the journal Aquatic Sciences – Research Across Boundaries. Since 2003 she is a member of the United Nations Environment Programme (UNEP) Environmental Effects Assessment Panel (EEAP).
Practical information
- General public
- Free
- This event is internal
Organizer
- IIE - EESS
Contact
- Prof. Samuel Arey, EESS coordinator