Structural Game of Urban Heat Load: How Morphological Evolution Reshapes Global Urban Climate Adaptation and Energy Strategy

Cities, as a core unit for climate change adaptation and mitigation, are facing unprecedented thermal stress. As global warming intensifies, the internal thermal environment of cities continues to rise, and the growth of Urban Cooling Demand (UCD) is no longer linear but is coupled with the complex evolution of the city's physical form. Understanding this coupling mechanism is key to formulating effective urban climate resilience strategies.

The research focuses on three core processes of urban volume evolution: lateral expansion, structural development (such as vertical densification), and infilling. These processes jointly shape the city's "volumetric growth" pattern, and the contribution of different patterns to the thermal load is entirely different.

On one hand, cities that undergo large-scale, irregular lateral expansion may have lower initial thermal loads, but their relative growth rate of UCD might be the fastest, suggesting a high sensitivity of the thermal environment to rapid spread at the periphery.

On the other hand, medium-sized cities may maintain the highest absolute thermal loads, reflecting the amplifying effect of their inherent density and spatial configuration on the urban heat island effect. In contrast, cities exhibiting compact urban forms tend to have a gentler trend in thermal load growth, which in a certain sense foreshadows the structural advantages of verticalization and high-density construction in achieving climate response and energy efficiency.

The core insight here is that the driver of urban thermal load is not solely determined by climate change or population growth, but by the mediating variable of the city's "form." This means the urban structure is no longer a static background but a dynamic variable that determines climate adaptation capacity and energy consumption patterns.

From the perspective of global urban competition and governance, this heterogeneity in form means that competition among global urban agglomerations is no longer just a race for economic scale but has evolved into a competition for different spatial strategies. City managers must move beyond the traditional narrative of "megacity development" and shift to finely manage the trajectory of their spatial evolution, balancing the expansiveness of expansion with the adaptability of density. This requires urban strategy to shift from macro-level land-use planning to micro-interventions in the "volumetric growth" process, such as guiding the city towards forms with greater structural resilience.

On a deeper level, the research reveals the intertwining of urban thermodynamics and social equity. The distribution of thermal load is not uniform, and different residents within the same city face significant social inequality in the risk of extreme high temperatures. Therefore, when choosing the evolution of urban form, the dimension of social equity must be incorporated into climate risk assessments to ensure that the costs and benefits of climate adaptation are distributed more equitably.Therefore, the evolution choices of urban form must incorporate the dimension of social equity when assessing climate risks, ensuring that the costs and benefits of climate adaptation are distributed more fairly.

Future urban strategy frameworks urgently need to integrate climate science, urban morphology, and energy system models to establish a predictive model that can quantify the impact of different growth patterns on UCD. Only by incorporating the evolution of urban form into the decision-making chain for climate adaptation can we truly achieve a paradigm shift from passively responding to climate risks to actively shaping climate-resilient spaces. This is not just a problem of engineering or urban planning; it is a reflection of the urban civilization's profound philosophical reflection on its spatial order when facing the challenges of global warming and capital restructuring.