Carbon Credits

An innovative method to calculate CO2 offset credits from high-solar reflective surfaces.

In hot climate regions like much of Latin America, a sizable portion of the energy supply—approximately half—is dedicated to cooling indoor spaces in homes and businesses. This heavy reliance on cooling systems places considerable strain on local economies. It perpetuates a cycle where the carbon dioxide emissions required to power these cooling mechanisms contribute to escalating temperatures. Consequently, the demand for cooling energy intensifies, perpetuating a loop of increased carbon emissions and heightened warming. This interconnected cycle underscores the urgent need for sustainable solutions to break the cycle of escalating energy consumption and environmental degradation in these regions.
Studies from the Berkeley Laboratory in California underscore the potential of solar-reflective roofing in mitigating these challenges. They reported that the widespread adoption of reflective roofing could yield a global cooling effect equivalent to removing 24 gigatons of carbon dioxide from the atmosphere. To put this into perspective, it equates to eliminating the emissions of 300 million cars over a span of 20 years. Furthermore, high solar-reflective roofs, also referred to as high-albedo, passively cool the interior of the structures, saving energy.
At the Urban Heat Island Conference hosted at RMIT University in Melbourne, Australia, from December 4-7, 2023, distinguished climate scientist and Nobel laureate Prof. Hashem Akbari, PhD, unveiled his latest research on calculating carbon offsets. The study is titled “A Simplified Method to Calculate Atmospheric CO2 Equivalency for Changing Surface Albedo.” This research, authored by Hashem Akbari and the Heat Island Group at Concordia University in Montreal, Canada, introduces a straightforward methodology for determining the atmospheric CO2 equivalency associated with altering surface albedo.
According to H. Akbari’s research presented in Melbourne in 2023, the implementation of high-albedo urban surfaces not only facilitates passive cooling but also generates an additional environmental benefit. By reflecting a greater portion of solar shortwave radiation back into space, these surfaces create a negative radiative force (RF). This counteracts the RF induced by the accumulation of greenhouse gases, primarily CO2, in the atmosphere.
In their study, H. Akbari and colleagues calculated using data from approximately 4400 weather stations worldwide. Their findings revealed that for every 0.01 increase in surface albedo, the median CO2 offset globally amounted to about 2 kg per square meter. Notably, regions with higher atmospheric transmittance, particularly those characterized by hot weather climates, demonstrated the highest levels of CO2 offset. This emphasizes the significant potential for mitigating carbon emissions through the widespread adoption of high-albedo urban surfaces, particularly in areas with elevated temperatures.