What impact does green infrastructure have on urban resilience to extreme weather events?

Green infrastructure can make a city less vulnerable to heat, heavy rain, and some storm impacts by letting natural processes do part of the work. Parks, wetlands, street trees, rain gardens, and green roofs all help manage water or moderate local temperatures.

During intense rainfall, planted areas and permeable surfaces absorb and slow runoff, reducing pressure on drains and lowering the risk of flash flooding. This can be especially valuable where runoff overwhelms combined sewer systems. Trees and vegetated roofs also provide shade and evaporative cooling, which can reduce exposure to extreme heat and soften urban heat islands. Wetlands and coastal vegetation may buffer some wave and flood impacts, depending on their location and condition.

The protection is meaningful but not absolute. A park cannot prevent every flood, and green features need space, upkeep, and suitable design to work well. Cities often get the strongest results by combining them with conventional drainage and flood protections, and by prioritizing neighborhoods with the greatest heat or flood risk. In practice, a connected tree canopy, green roofs, and rain gardens can make streets and buildings more resilient while also improving everyday public space.