The Paris Agreement on climate change will transform the global energy system for decades to come, according to the authors of this executive summary, which summarizes the latest World Energy Outlook, a comprehensive analysis of what this transformation of the energy sector might look like, thanks to its energy projections to 2040. The report reviews the key opportunities and challenges ahead for renewable energy, the central pillar of the low-carbon energy transition, as well as the critical role for energy efficiency. It examines how a post-Paris world redefines the idea of energy security, particularly in the power sector. The report explores how oil, natural gas and coal are adjusting to today’s market conditions and assesses the risks that lie ahead, from under-investment in essential supply to stranded assets. It looks at individual country pledges and examines how close—or far—nations are from reaching their goals. It outlines a course that would limit the rise in global temperature to below 2°C and also plots possible pathways for meeting even more ambitious goals. This year, the World Energy Outlook devotes a special chapter to the critical interplay between water and energy, with an emphasis on the stress points that arise as the linkages between these two sectors intensify.