Reflective surfaces or ground-based albedo modification (GBAM) is a solar radiation management method of enhancing the Earth's albedo (the ability to reflect the visible, infrared and ultraviolet wavelengths of the sun, reducing heat transfer to the surface). The IPCC described this method as "whitening roofs, changes in land use management (e.g., no-till farming), change of albedo at a larger scale (covering glaciers or deserts with reflective sheeting and changes in ocean albedo)." The most well-known type of reflective surface is a type of roof called the "cool roof". While cool roofs are mostly associated with white roofs, they come in a variety of colors and materials and are available for both commercial and residential buildings. Method As a method to address global warming, the IPCC 2018 report indicated that the potential for global temperature reduction was "small," yet was in high agreement over the recognition of temperature changes of 1-3°C on a regional scale. Limited application of reflective surfaces can mitigate urban heat island effect. Reflective surfaces can be used to change the albedo of agricultural and urban areas, noting that a 0.04-0.1 albedo change in urban and agricultural areas could potentially reduce global temperatures for overshooting 1.0°C. The reflective surfaces approach is similar to passive daytime radiative cooling (PDRC) being that they are both ground-based, yet PDRC focuses on "increasing the radiative heat emission from the Earth rather than merely decreasing its solar absorption." Types of reflective surfaces Cool Roofs Benefits Cool roofs, in hot climates, can offer both immediate and long-term benefits including: Savings of up to 15% of the annual air-conditioning energy use for a single-story building Help in mitigating the urban heat island effect. Reduced air pollution and greenhouse gas emissions, as well as a significant offsetting of the warming impact of greenhouse gas emissions. Cool roofs achieve cooling energy savings in hot summers but can increase heating energy load during cold winters. Therefore, the net energy saving of cool roofs varies depending on climate. However, a 2010 energy efficiency study looking at this issue for air-conditioned commercial buildings across the United States found that the summer cooling savings typically outweigh the winter heating penalty even in cold climates near the Canada–US border giving savings in both electricity and emissions. Without a proper maintenance program to keep the material clean, the energy savings of cool roofs can diminish over time due to albedo degradation and soiling.