"We recognize the importance of renewable energy for sustainable development, diversification of energy supply, and preservation of the environment. We will ensure that renewable energy sources are adequately considered in our national plans and encourage others to do so as well. We encourage continuing research and investment in renewable energy technology, throughout the world". Communique from the G8 Leaders' Summit, Genoa, July 2001. The Third Assessment Report of the IPCC confirmed that the Earth's climate is changing as a result of human activities, particularly from energy use, and that further change is inevitable. Natural ecosystems are already adapting to change, some are under threat, and it is evident that human health and habitats will be affected world-wide. Such climate changes could also affect the present supplies of renewable energy sources and the performance and reliability of the conversion technologies. This paper concentrates on the reduction of carbon dioxide emissions and the role that the global renewable energy industry might play in this regard. (The five other major greenhouse gases are given less emphasis here.) The paper compares the costs of renewable energy systems with fossil fuel-derived energy services and considers how placing a value on carbon emissions will help provide convergence. The move towards a de-carbonised world, driven partly by climate change science and partly by the business opportunities it offers, will need to occur sooner rather than later if an acceptable stabilisation level of atmospheric carbon dioxide is to be achieved. Government policy decisions made now will determine the sort of future world we wish our children to inherit. The renewable energy era has begun. (C) 2003 Elsevier Ltd. All rights reserved.