Adapting cities to climate change

Relentless floods. Searing Heat. Vanishing coastlines. Thailand’s cities are under siege from climate risks. Without urgent intervention, the worst is yet to come.
The evidence is clear: Cities in Thailand are grappling with triple climate challenges — rising temperatures, destructive floods, and coastal erosion.
These threats do not endanger lives and ecosystems. They also cause significant economic loss since cities are the backbone of the economy.
Globally, cities generate 80% of GDP while hosting over 56% of the population. Repeated extreme weather events can lead to economic disaster.
Thailand is no exception.
Over half of Thailand’s population now lives in cities, and this number is growing along with the risks of heatwaves, flooding, and coastal erosion.
In Bangkok, urban heat islands have caused city temperatures to rise by 5.26C over the past 25 years, according to a study by the Asian Institute of Technology and Khon Kaen University in 2020.
Chiang Mai, known for its cool climate, now experiences temperatures over 36C in many areas. Another study from Burapha University in 2019 also mentioned that rapid urbanisation and shrinking green spaces have made the eastern region 2.56C hotter over the last decade.
As a result, deaths from heat waves have surged. Vulnerable groups, such as outdoor workers, the elderly, and slum dwellers, are hit the hardest, exacerbating Thailand’s already distressing inequality.
Flooding is a major issue in Bangkok, with 737 flood hotspots, according to the data from the Bangkok Metropolitan Administration, worsened by more rainstorms. Floods disrupt daily life, cause traffic gridlock, and damage infrastructure, causing significant economic loss.
During rush hours, heavy rain can cause up to 2,000 hours of travel delays daily alone. This number might seem to be small, but the calculation is based on the traffic situation at only 16 major intersections in Bangkok.
As Bangkok sinks, rising seas will worsen the problem, while flash floods become more common. Chiang Mai, the largest city in the North, suffered unprecedented flooding this year, highlighting the need for better preparedness and action.
Despite the devastation year after year, current flood prevention measures like barriers and drainage systems are short-term fixes. Sustainable solutions require comprehensive river basin management, better water-retention areas, and long-term city planning, including active community involvement.
Rising sea levels and stronger storms have eroded 26% of Thailand’s 3,151-kilometre coastline. Over the past 30 years, the country has lost around 100,000 rai of coastal land, with Bangkok’s Bang Khun Thian losing 2,735 rai.
This erosion threatens cities, communities, ecosystems, and the economy, displacing villages and destroying vital ecosystems like mangroves. Urgent action is needed to protect the coastline.
Current efforts to address heatwaves, flooding, and coastal erosion are sadly fragmented and inadequate.
As cities grow hotter, the government has done little — if anything — to expand green spaces, promote eco-friendly buildings, or invest in long-term solutions.
Some measures, like taxing water retention areas as unproductive lands, have made things worse by reducing flood absorption areas. Concrete sea walls, built without comprehensive environmental studies or local input, have also worsened coastal erosion nearby, showing the flaws of relying solely on hard engineering solutions from a top-down policy.
Long-term flood prevention is also lacking. Flood walls and drainage upgrades, for example, address the symptoms, not the root causes.
Sustainable approaches require ecological planning, sufficient water retention, inclusive city planning and community involvement. Additionally, environmental and social assessments need to be fair, transparent, and participatory, which they are not at present.
Piecemeal solutions do not work. The impacts of climate change are not just environmental — they are also economic and social crises. What Thailand needs is a cohesive, long-term strategy to make cities climate resilient, and there is much to learn from other countries.
After deadly heatwaves in 2022 that claimed 425 lives in Phoenix, US, mainly among the homeless and the elderly — the city set up a data system to track vulnerable groups and give them easy access to shelters and water stations. It has saved lives and improved emergency responses.
Meanwhile, London uses green, environmen- tally friendly buildings through collaboration between local government, the private sector, building owners, and climate experts to tackle rising temperatures.
Copenhagen, Denmark, after dealing with repeated heavy rain and flooding, has created dual-purpose parks that act as floodwater reservoirs during storms. The city has also built giant underground tunnels to separate rainwater from sewage, helping improve climate resilience and urban liveability.
In China, “sponge cities” are being developed to fight severe flooding. These cities use parks to absorb rainwater, temporary water-retention areas, and roads designed to soak up water and slow runoff.
After the 1953 North Sea flood that killed 1,800 people and flooded 9% of the Netherlands, the government used modern sea wall technology to prevent future floods. They also listened to local fishermen’s input to adjust the project and improve its effectiveness.
Closer to home, Singapore is fighting city heat with better urban planning. This includes improving cooling systems, reducing car use, building eco-friendly structures, and adding more green, open spaces across the city.
In Indonesia, Jakarta’s flooding problem is being tackled by planting mangroves, clearing garbage to improve water flow, and relocating people from flood-prone areas with community input. These areas are being turned into water-retention zones. Indonesia is also moving its capital from Jakarta to the island of Borneo.
International examples offer practical and effective strategies for making cities resilient to climate risks — valuable lessons for Thailand.
To fight heatwaves, cities can add more green spaces, reduce car use, and improve air conditioning systems. Green buildings, like those with rooftop gardens, can also help cool urban areas.
For flooding, adding green spaces, improving drainage, and building “sponge cities” that soak up water can reduce damage from heavy rains.
To protect coastlines, planting mangroves, restoring natural ecosystems, using innovative engineering, and relocating buildings from high-risk areas are essential steps.
These solutions combine nature, smart engineering, and community support to address climate challenges effectively. They can be grouped into four colour-coded strategies. Grey focuses on traditional engineering, green on eco-friendly, natural solutions, blue on water absorption, and white on relocation.
Importantly, all these strategies prioritise local knowledge and input, using a participatory process to help residents adapt their habits and behaviours.
The solution is simple: reduce car use and improve air conditioning to cut emissions, make buildings eco-friendly, and expand green spaces, water-retention areas, and mangroves. Focus on new ideas and involve local communities. If needed, relocate people from high-risk areas.
Adapting cities to climate change begins with understanding the risks, identifying vulnerable groups and dangerous areas, and checking if the city is ready to respond. This means reviewing city infrastructure, working together with all stakeholders, and creating long-term plans for sustainable growth.
Cities need strong plans, careful assessments, and smart investments in solutions that tackle multiple climate risks. For Thailand, this means adding more green spaces, turning unused urban land into parks or wetlands with tax incentives, updating old buildings to be eco-friendly, and relocating risky developments with fair compensation and community input.
These actions can help our cities prepare for climate change. For sure, adaptation will not be cheap, but the price of doing nothing will be far greater. The time to act is now.
Sumet Ongkittikul, PhD, is vice president for internal systems and research director of transportation and logistic policy, and Nuntachart Ratanaburi is a researcher at the Thailand Development Research Institute (TDRI). This article is the author’s adaptation from his presentation ‘Making Cities Resilient to Climate Change’ at the 2024 TDRI Annual Public Conference on Oct 30, 2024.