Sir Mark has lucidly addressed the growing demand for accessible energy throughout the world, the need for basic provision of energy to one third of the world's population and the conflicts that arise between the ways in which energy is supplised and used and the constraints of sustainability. It is, of course, the innovation, creativity and activity of industry that will provide solutions to the problems we face. It is therefore appropriate and helpful to hear form one of the leaders of the energy industry. The vision he presents i one of a vibrant, innovation, market-driven industry operating within a regulatory framework that gives the maximum flexibility for creative solutions. The greatest challenges faced by the world energy sector are concerned with environmental sustainability. Because the emissions of greenhouse gases such as carbon dioxide spread rapidly around the globe, sustainability has to be considered on a global basis and global solutions are rquired. International agreements concerning action, for instance the Framework Convention on Climate Change (FCCC), need to be based on sound science and on four widely accepted principles, namely the Precautionary Principle, the Polluter Pays Principles and the Principles of Sustainable Development and Equity. The challenge to the FCCC is to devise mechanisms and arragements that will bring about substantial reductions in greenhouse gas concentrations in the atmosphere and that also satisfy there principles. A recent Energy Review from the Policy Innovation Unit of the UK Government's Cabinet Office has considered in detail how a sustainable energy strategy can be developed. Finally, reasons are given for optimism that, given the necessary commitment by the world community, a sustainable energy strategy for the world can be developed and realised during the 21st century.