Assessing Worldwide Radiative Cooling toward Global Warming Mitigation

Abstract Radiative cooling (RC) passively cools terrestrial objects by radiating heat into outer space, providing a fuel-free means for addressing energy and environmental challenges. However, its potential to mitigate global warming at the planetary scale remains unquantified. Herein, we examine global RC power on an annual time scale, which is vital for implementing RC-based technologies. We propose a meteorological data-based model and quantify the RC power across ∼2000 global cities. The geographic disparities of global RC power are analyzed. Regions with temperature reductions exceeding 6 °C and those with RC power over 80 W m–2 are highlighted. Based on the year-round cooling power, we categorize the global RC map into five representative regions. Furthermore, we estimate the CO2 emission reduction of RC deployment and define a theoretical threshold area required to rebalance Earth's energy budget. These results provide a quantitative basis for guiding worldwide RC deployment toward global warming mitigation.