Principal Voices is a project aimed at stimulating discussion on some of the major challenges facing our world today.

Through 2005 TIME, FORTUNE and CNN, in association with Shell, will be bringing together a group of globally-renowned experts - Principal Voices - in a series of videos, articles and round-table discussions.

Themes covered will include the environment, business innovation, economic development and transport. The Principal Voices will explore some of the key issues involved in these areas, and offer their ideas and opinions on how to meet the challenges facing the planet as we move forward into the 21st Century.