Historically, energy transitions have been multi-faceted. Biomass is the energy source from which the world transitioned into coal. Yet even that initial transition is far from finished. Globally more than 2.6 billion people do not have access to clean cooking fuel. For these people, including much of the population in sub-Saharan Africa, the shift from biomass to LPG for cooking will be a 21st century energy transition that will reduce local air pollution, improve health and livelihood and spare women the hours spent gathering wood. Staggering growth in energy demand appears ahead, even with continuing improvement in energy efficiency. Energy transitions are not new. But this one is different because of that imperative to reduce emissions while at the same time enabling energy consumption to continue to grow. Other key differences are the speed and all-encompassing scale it implies—net-zero by 2050. In prior transitions, externalities such as the impact and cost of emissions were not considered. These differentiators make this transition—untested in the history of energy—more challenging than any previous energy transitions. This transition is driven more by policy and market interventions aimed at reducing emissions, than by market economics and technology. Previous energy transitions have unfolded over a century or more, not in a quarter of a century. Moreover, energy transitions have not reduced or replaced the existing energy base before the new energy base was ready; instead, they resulted from new sources being added atop the existing mix. In short, global energy systems cannot be rebuilt overnight. Capital stock, i.e., hardware has a lifespan of decades and cannot be changed as quickly as software. The target to achieve net zero by mid-century is extremely challenging as evidenced by the quick rebound in emissions in 2021-22 after the drop in 2020 due to COVID-19. What is the realistic pace of change for energy and emission transitions without leading to unintended consequences? Will consumers have to pay higher energy prices for the foreseeable future to reduce emissions? How should energy transition play out in emerging economies where emissions may continue to increase for some years before reversing the trend? How can the transition be just, orderly and “well managed”? What will this require?