Problems with energy supply and use are related not only to global warming, but also to such environmental concerns as air pollution, ozone depletion forest destruction and emission of radioactive substances. These issues must be taken into consideration simultaneously if humanity is to achieve a bright energy future with minimal environmental impacts. Much evidence exists which suggests that the future will be negatively impacted if humans keep degrading the environment. There is an intimate connection between energy, the environment and sustainable development. A society seeking sustainable development ideally must utilize only energy resources which cause no environmental impact (e.g. which release no emissions to the environment). However, since all energy resources lead to some environmental impact, it is reasonable to suggest that some (not all) of the concerns regarding the limitations imposed on sustainable development by environmental emissions and their negative impacts can be in part overcome through increased energy efficiency. A strong relation clearly exists between energy efficiency and environmental impact since, for the same services or products, less resource utilization and pollution is normally associated with higher efficiency processes. Anticipated patterns of future energy use and consequent environmental impact (focusing on acid precipitation, stratospheric ozone depletion and the greenhouse effect) are comprehensively discussed in this paper. Also, some solutions to current environmental issues in terms of energy conservation and renewable energy technologies are identified and some theoretical and practical limitations on increased energy efficiency are explained. The relations between energy and sustainable development, and between the environment and sustainable development, are described, and an illustrative example is presented. Throughout the paper several issues relating to energy, environment and sustainable development are examined from both current and future perspectives. Finally, several conclusions and recommendations are drawn which may be useful to energy scientists and engineers and policy makers.