How long will conventional fossil fuels remain the predominant source of energy? Does nuclear power have a future? What new energy technologies are emerging on the horizon? What are the implications of the growing role played by developing countries as producers and users of energy? What can be done to avoid international energy crises in the future? How will the information society affect the production and use of energy? And what will be the long-term implications of international environmental agreements for a sustainable energy future? Endeavours to set world energy on a sustainable footing are entering a critical phase. By 2050 the energy landscape could be completely transformed. A highly diversified mix of conventional and new fuels will be in use; unprecedented levels of energy efficiency in transport systems, housing and other infrastructures will likely have been attained; and people could at last be reaping the rewards of environmentally responsible lifestyles. But such a shift towards sustainable use of energy will take decades to achieve. This book reviews the options likely to shape the energy picture over the next half-century, and assesses some of the key issues -- economic, social, technological, environmental -- that decision-makers in government and corporations will need to address in the very near future.