Part 1 | Part 2 | Part 3 James Hansen is known as the 'grandfather of climate change' and is perhaps the world's leading authority on the science of climate change. He is director of the NASA Goddard Institute for Space Studies, New York and Adjunct Professor at Columbia University’s Earth Institute and has for the last 30 years focused on climate research, publishing more than 100 scholarly articles on the topic. In this Sydney lecture he delves into the latest climate science, addresses the gap between the certainty of the science and the rise of climate changes scepticism, and also discusses the pros and cons of the world's energy options, from nuclear to the (to his mind unlikely) viability of clean coal, as well as the various options for the necessary emissions reduction. Presented by Sydney Ideas and the United States Studies Centre, March 2010