Speaker: Danny Harvey
Department of Geography UofT
Title: Constraining fast and slow climate feedbacks with computer models
The climate system responds to radiative forcings (such as changes in solar luminosity or in greenhouse gas concentrations due to human emissions) through a variety of feedback mechanisms. Some of these, such as those involving water vapour, clouds, and seasonal snow and ice, are termed "fast" feedbacks and respond within weeks to years. Others, termed "slow" feedbacks, respond on a time scale of decades to millenia and can greatly amplify the response due to fast feedbacks. Geological data can be used to constrain both fast and slow feedbacks, but this requires reconstructing both past radiative forcings and past climate conditions. Much of the evidence in based on various isotope ratios in materials found in sediments from the past (going back hundred of millions of years), but the interpretation of this evidence requires the used of models of the long term cycling of the elements and isotopes in question. The broad outlines of how this is done will be introduced in this talk.
Danny Harvey is Professor in the Department of Geography at the
University of Toronto. He studied Geography at the University of British
Columbia (B.Sc.) and University of Toronto (M.Sc. & Ph.D.),
obtaining his Ph.D. in 1986. Dr. Harvey pursues research in the areas
of computer climate modelling as well as options to reduce emissions of
greenhouse gases associated with energy use. His modeling work is
focused on understanding past climatic changes and projection of future
climatic change due to emissions of greenhouse gases, with a particular
emphasis on coupled climate-carbon cycle models and the impacts of
different future global energy scenarios.
The Collaborative Challenges for
the Climate Change Research Community (CCCCRC or C4RC) is a weekly
seminar series highlighting trans-disciplinary research in climate
change, with a goal in fostering meaningful collaboration between
climate change researchers. Our aim is to use this as an exploration
of the range of research related to climate change across the
University of Toronto, and to inspire new collaborations. A central
theme of the series is the role of computational climate models: how
researchers share models, verify models, create models, and share
results. All are welcome to attend the series.