This lecture discusses the energy requirements for producing various materials, focusing on metals and their environmental impact. It begins with an overview of global carbon emissions by sector, highlighting the significant contribution of steel production. The instructor presents data on energy consumption for different materials, emphasizing the high energy intensity of aluminum and steel. The lecture further explores the relationship between energy consumption and carbon emissions, detailing how energy-intensive processes contribute to the overall carbon footprint. The discussion includes the thermodynamic limits of metal extraction and the energy costs associated with separating metals from their ores. The instructor also addresses recycling rates and the energy savings achieved through recycling compared to primary production. The lecture concludes with insights into the evolving energy efficiency of material production processes and the importance of technological advancements in reducing energy consumption and environmental impact.