Topic: Global Warming: Evidences, Causes and Long-term Impacts
Speaker: Bala Govindasamy, Lawrence Livermore National Laboratory
Date & Time: Tuesday, April 11, 2006, 10:00 AM
Place: Room 140 VMC (Chambers Hall)
The complexity of the climate system demands an integrated approach to understand the feedbacks between different components. In this talk, we focus on the coupling between the physical climate system and carbon cycle. Progress from a global coupled climate-carbon cycle model, INCCA, developed at Lawrence Livermore National Laboratory will be discussed. The model simulates the historical global mean surface temperature, land and ocean carbon fluxes, and atmospheric CO2 in good agreement with observations. We have used this model to address the global climate and carbon cycle changes out to year 2300 that would occur if CO2 emissions from all the currently estimated conventional fossil fuel resources (oil, gas, coal) were released to the atmosphere. By year 2300, the global climate warms by about 8oC and atmospheric CO2 reaches 1423 ppmv. In the polar region, the simulated warming is over 20oC. Nearly 45 % of cumulative emissions remain in the atmosphere. Large -scale changes in vegetation distributions are projected. Strong acidification of ocean that is harmful to marine organisms with shells is predicted. Despite having relatively lower climate sensitivity and strong carbon uptake by the land biosphere, our model projections suggest severe long-term consequences for global climate if all the fossil-fuel carbon is ultimately released to the atmosphere.
Dr. Bala is presently a climate scientist at Lawrence Livermore National Laboratory. He is an expert in earth system modeling and on climate change issues. His major research interests include climate, water and carbon cycle issues. Dr. Bala received his doctorate in 1994 from McGill University, Canada in Atmospheric and Oceanic Sciences. After spending two year as a visiting scientist at Princeton University, he joined the Lawrence Livermore National Laboratory (LLNL). At Livermore Lab, Dr. Bala has investigated climate change due to greenhouse gases and land cover changes. He has authored seminal papers on climate modeling of mitigation of climate change via macro-engineering schemes. Dr. Bala is the lead author of a recent study, published in Journal of Climate, that investigated the climatic and carbon cycle consequences of emitting all the currently estimated conventional fossil-fuels to the atmosphere by the year 2300. This modeling study projected severe long-term consequences for global climate, terrestrial ecosystems, and marine life; a global warming of 15 degrees F and the disappearance of Tundra and ice caps in the Arctic by the year 2300.
Refreshments will be served at 9:45 PM