The absence of vegetation in urban areas contributes to the establishment of the urban heat island, markedly increasing thermal stress for residents, driving morbidity and mortality. Mitigation strategies are, therefore, needed to reduce urban heat, particularly against a background of urbanization, anthropogenic warming and increasing frequency and intensity of heatwaves. In this Review, we evaluate the potential of green infrastructure as a mitigation strategy, focusing on greenery on the ground (parks) and greenery on buildings (green roofs and green walls). Green infrastructure acts to cool the urban environment through shade provision and evapotranspiration. Typically, greenery on the ground reduces peak surface temperature by 2–9 °C, while green roofs and green walls reduce surface temperature by ~17 °C, also providing added thermal insulation for the building envelope. However, the cooling potential varies markedly, depending on the scale of interest (city or building level), greenery extent (park shape and size), plant selection and plant placement. Urban planners must, therefore, optimize design to maximize mitigation benefits, for example, by interspersing parks throughout a city, allocating more trees than lawn space and using multiple strategies in areas where most cooling is required. To do so, improved translation of scientific understanding to practical design guidelines is needed.

城市地区缺乏植被有助于建立城市热岛，显着增加居民的热应激，导致发病和死亡。因此，需要采取缓解策略来减少城市热量，尤其是在城市化，人为变暖以及热浪频率和强度增加的背景下。在本综述中，我们评估了绿色基础设施作为缓解策略的潜力，重点是地面（公园）的绿化和建筑物（绿色的屋顶和绿化的墙壁）上的绿化。绿色基础设施通过遮荫和蒸散作用为城市环境降温。通常情况下，地面上的绿色植物会使峰值表面温度降低2–9°C，而绿色屋顶和绿色墙壁会使表面温度降低〜17°C，还为建筑物围护结构提供了额外的隔热。但是，根据潜在的规模（城市或建筑物的高度），绿化程度（公园的形状和大小），植物的选择和植物的放置，冷却潜力会显着变化。因此，城市规划人员必须优化设计，以最大程度地减少污染，例如，在整个城市中穿插公园，分配比草坪更多的树木，并在需要最大制冷量的区域使用多种策略。为此，需要将科学理解转化为实用的设计指南。优化设计以最大程度地减少污染，例如，在整个城市中穿插公园，分配比草坪空间更多的树木，并在需要冷却的区域使用多种策略。为此，需要将科学理解转化为实用的设计指南。优化设计以最大程度地减少污染，例如，在整个城市中穿插公园，分配比草坪空间更多的树木，并在需要冷却的区域使用多种策略。为此，需要将科学理解转化为实用的设计指南。