Green Infrastructure to Combat Urban Heat Islands, Breathing Life into Gray Cities

As record heat waves become commonplace, cooling down the scorching cities has become an urgent priority.

The importance of building 'Green Infrastructure' as a survival strategy for cities in the era of climate crisis is emphasized more than ever. It is considered the most effective and sustainable alternative to the 'urban heat island phenomenon' that traps heat in gray cities covered with asphalt and concrete.

Green Infrastructure is an approach that integrates nature-based solutions into urban planning, including rooftop greening, wall greening, permeable pavements, artificial wetlands, and urban forests. It performs various functions that fundamentally address urban environmental issues, going beyond mere aesthetic improvements.

The most direct effect is the reduction of urban temperatures. Plants cool the surrounding air through transpiration, and green spaces block direct sunlight, reducing the solar heat absorbed by buildings.

According to research by the National Institute of Forest Science, rooftop greening can lower indoor temperatures on the top floors of buildings by up to 4.5℃ and reduce summer cooling energy by about 17%. This has a dual effect of contributing to greenhouse gas reduction.

Additionally, green infrastructure restores the urban water circulation system. Instead of impermeable pavements that cannot absorb rainwater, using permeable materials allows rainwater to seep into the ground, reducing the risk of urban flooding and alleviating groundwater depletion issues.

Rain gardens or artificial wetlands serve as natural filters that store rainwater while purifying pollutants.

The benefits of improving air quality and enhancing biodiversity cannot be overlooked. Lush street trees and urban forests absorb fine dust and provide fresh oxygen. Moreover, urban green spaces offer habitats for wildlife and play a crucial role in connecting fragmented ecosystems.

Recently, the city of Seoul has been accelerating the expansion of such green infrastructure. It is expanding support for rooftop gardens and wall greening projects for major urban buildings and is pursuing an ambitious plan to increase urban green space by 15% by 2030.

Advanced cities abroad are also actively adopting various forms of green infrastructure, such as Germany's 'Wind Path Forest' and Singapore's 'Vertical Gardens'.

In an era where heat waves and heavy rains are becoming more frequent due to climate change, expanding green infrastructure is a key investment to enhance urban resilience.

By creating green breathing spaces in the gray forest of buildings, cities can finally ensure the quality of life for citizens and secure a sustainable future.