From fossil fuels to photovoltaics: energy's role in human development and sustainability

Abstract

The evolution of human civilization—from subsistence societies to a globally productive and interconnected economy—has been fundamentally driven by our evolving ability to harness energy. Each major transition in our dominant fuel source—from biomass to coal, then to oil and gas—has marked a pivotal turning point in productivity, economic development, and global well-being. Perhaps our greatest achievement is lifting large portions of humanity above poverty; today, global productivity surpasses the threshold needed to universally eliminate poverty more than twentyfold. However, reliance on fossil fuels has brought serious unintended consequences: rising greenhouse gas emissions, mounting waste, and accelerating biodiversity loss, threatening the stability of the very systems enabling prosperity. Addressing these challenges requires a transformation of our energy system as a foundational step toward sustainability. This paper argues that transitioning toward decarbonized and circular infrastructures is both technically and economically feasible, requiring investments on the order of 1% of global GDP—a figure consistent with multiple global assessments. Among available technologies, photovoltaics emerge as uniquely scalable, mature, and rapidly advancing. With over 2 TW installed capacity and utility-scale electricity costs below 1.5 cents per kilowatt-hour, solar energy has become the fastest-developing energy source in history. Promising advancements, particularly perovskite-based photovoltaics combined with circular material strategies, could boost the energy return on investment (EROI) beyond 90. By aligning our productivity with ecological boundaries through innovations in solar energy, we have the opportunity to redefine prosperity—making sustainability a source of economic growth, improved public health, global equity, and environmental resilience.