The Global Warming Potential of Geoengineering via Radiative Cooling

Abstract

This paper analyzes the potential to mitigate global warming using radiative cooling (RC) surfaces on a large scale. The study evaluates the net cooling power, radiative forcing (RF), and global warming potential of different RC materials compared to conventional construction and roofing materials, Earth's natural surfaces, and some reference cases. Key parameters for evaluating the above-mentioned structures include their solar reflectance (albedo) and long-wavelength infrared emissivity. Results show the cooling power that can be achieved by an ideal RC material with a solar reflectance of 100% and long-wave infrared emissivity of 100% is 164.8 W·m⁻². In practice, materials exhibiting a cooling power as high as 160.8 W·m⁻² are fabricated. Further analysis shows if 1% of Earth's surface are to be covered with this material the terrestrial RF will decrease by 1.61 W·m⁻² (from 0.6 to −1.01 W·m⁻²). The results demonstrate that RC materials with high solar reflectivity and emissivity offer substantial cooling benefits and can reduce RF when implemented on large scales. The findings underscore the effectiveness of RC materials in reducing global warming and provide a valuable perspective on their role in reducing the environmental impacts of the built environment.