Enhancing Urban Climate-Energy Modeling in the Community Earth System
Model (CESM) through Explicit Representation of Urban Air-conditioning
Adoption
Abstract
Improved representation of urban processes in Earth System Models (ESMs)
is a pressing need for climate modeling and climate-driven urban energy
studies. Despite recent improvements to its fully coupled building
energy model, the current Community Land Model Urban (CLMU) in the
Community Earth System Model (CESM) lacks the infrastructure to model
air-conditioning (AC) adoption explicitly. This undermines CESM’s
fidelity in modeling urban climate and energy use, and limits its use in
climate and energy risk assessments. Here, we establish an
explicit-AC-adoption parameterization scheme in CESM that represents AC
adoption explicitly through an AC adoption rate parameter in the
Building Energy Model of CLMU, and build a present-day, global,
survey-based, and spatially explicit AC adoption rate dataset at country
and sub-country level that is integrated within CESM. The new dataset
can be leveraged for other ESMs or global-scale models and analyses. The
explicit AC adoption scheme and the AC adoption rate dataset
significantly improve the accuracy of anthropogenic heat modeling due to
AC in CESM. The new parameterization scheme makes it possible to
evaluate the effects of changing AC adoption on global urban energy and
climate using CESM. These developments enhance CESM in its use for
climate impact assessments under future climate and socioeconomic
development scenarios, and represent continued efforts in better
representing urban processes and coupled human-urban-Earth dynamics in
ESMs.