Urban Heat Islands

Cities are often several degrees warmer than the surrounding countryside.

城市的气温往往比周围的乡村高出几度。

This phenomenon, known as the urban heat island effect, has several causes.

这种现象被称为城市热岛效应，其成因有好几个。

Concrete and asphalt absorb heat during the day and release it slowly at night.

混凝土和沥青白天吸收热量，夜间再缓慢释放出来。

Air conditioners, vehicles and factories add even more heat to the environment.

空调、车辆和工厂还会向环境中排放更多热量。

The lack of trees means there is less shade and less natural cooling.

树木稀少意味着遮阴更少，自然降温的效果也更弱。

During heatwaves, these higher temperatures can pose serious health risks.

在热浪期间，这样的高温可能对健康造成严重威胁。

Planners are responding by planting trees and creating green roofs.

规划者们正通过植树和建造绿色屋顶来应对。

Some cities are also painting surfaces in light colours to reflect sunlight.

一些城市还把各种表面涂成浅色，以反射阳光。

Such measures can make urban life more comfortable and sustainable.

这些措施可以让城市生活更舒适、更可持续。