Description
What forces drive climate change? The objective of this e-seminar will be to provide class participants with an introduction to some of the factors (both natural and human induced) that drive climate change on a variety of timescales. In the first section of the e-seminar, Dr. Ortiz (pictured left) will discuss processes that drive climate change on timescales ranging from the seasonal cycle to variations in Earth's orbital geometry. In the second section, a study of the Monsoon system serves as an example of how some of these climatic-forcing functions interact. On seasonal timescales, Monsoon circulation systems in Africa, India and Asia are driven by the thermal contrast between land and sea. Likewise, during times in the geologic past when orbital parameters maximized seasonal contrast, enhanced Monsoon systems existed. This effect has been successfully simulated with global climate models (GCMs) and observed using geologic data such as lake level records. During the final section of the e-seminar, Dr. Ortiz will provide students with the context needed to help class participants begin an exploration of the issue of anthropogenic (human-induced) climate change as they read through a recent article by a world expert on the subject, Dr. James Hansen of NASA GISS.

Material presented in the e-seminar includes numerous links to climate-related Web materials and thought-provoking "challenge questions" related to climate materials presented during the workshop.