Mapping the relationship between urban form and CO2 emissions in three US cities using the Local Climate Zones (LCZ) framework

Understanding the relationship between urban form and CO2 emissions is essential for developing mitigation measures. However, most studies so far have been limited to examining the urban form at the macro level. Existing studies have limitations, such as a lack of granularity and a standardized approach, and focus on a limited set of urban form indicators. To address these issues, this study employs the Local Climate Zones (LCZ) framework to investigate the relationship between urban form and CO2 emissions at the micro level in three American cities: Baltimore, Indianapolis, and Los Angeles. Results indicate that LCZ offers a valuable framework for mapping emissions at the building and street level and facilitates a better understanding of different urban forms' emission behavior. According to the findings, emission intensity in compact areas with few or no trees and limited green space is up to 3.5 times higher than in areas characterized by open layouts, scattered trees, and abundant plant cover. Also, per capita emissions in compact areas are, on average, two times higher than in areas with more open layouts. Additionally, the results show that compact high-rise and mid-rise areas without trees and greenery (LCZ 1 and 2), particularly in Baltimore and Indianapolis, experience higher emissions levels than other LCZs during the daytime. The findings suggest that the LCZ framework holds promise for understanding the link between urban form and emissions in intricate urban settings, as well as for low-carbon urban planning and climate change mitigation.