This session will explore the rapidly changing geography of global science, how it is being transformed by international and cross-disciplinary collaboration, and the implications of these developments for addressing the "global challenges" of our time. In an ongoing study, in partnership with Elsevier, and due to report on 29 March 2010, this project is looking at how, why, where, and by whom science is being carried out across the world, and the ways in which this picture is changing. It will also focus on the growth of international collaboration in recent years and how this is being harnessed to tackle the most pressing problems facing society in the 21st century, such as climate change; food and energy security; and global health. It is commonplace that these "global challenges" are threats that affect all of humanity and will require solutions that transcend national borders and disciplinary silos. The crucial questions are whether scientific collaboration is currently being orchestrated and nurtured in the most effective manner to overcome these boundaries and address these issues, and how it could best be encouraged to do so in the future.