Current environmental problems have their roots in the dramatic improvements in living standards associated with technological and institutional developments since the Industrial Revolution. With this in mind, this paper investigates the relationships between economic development, energy use and environmental impacts in the very long run. It highlights how the role of energy services changes at different phases of economic development. It also stresses that energy transitions have had strong welfare and transformative effects, with many unexpected consequences, including for society and the environment. These issues should be explored in more detail when considering future economic growth and development, and energy transitions. Furthermore, due to technological, economic, political and social changes, it appears that the early twenty-first century may offer an opportunity for change in the economy’s trajectory – a critical juncture. Many feel that it is an opportunity to sway the economy towards a less natural-resource-intensive path – for instance, towards a low-carbon knowledge economy – and a delay to this intervention might lock the global economy on to an unsustainable path, risking long-run economic and social decline.