This lecture discusses the limits of growth in relation to technological progress and sustainability. It begins by addressing the historical context of energy consumption, highlighting the transition from biomass to fossil fuels and the implications of this shift. The instructor emphasizes the importance of understanding primary energy sources and their conversion into usable energy. The lecture explores the concept of limits to growth, referencing the influential book 'The Limits to Growth' and its predictions about resource depletion and environmental degradation. The discussion includes the challenges of creating sustainable systems, as illustrated by the Biosphere 2 experiment, which aimed to replicate Earth's ecosystems. The instructor also examines the social and health implications of energy consumption, particularly the inequalities exacerbated by fossil fuel dependency. The lecture concludes by stressing the need for a paradigm shift towards sustainable practices and the recognition of ecological limits, urging collective action to address these pressing issues.