Singapore as a global leader in urban heat governance - what can the world learn?

Global heat is a global problem 

Extreme heat poses a significant policy dilemma in the Anthropocene era. The year 2023 witnessed the highest temperature recorded since 1850, surpassing the pre-industrial average by 1.35 degrees Celsius. The period spanning from 2014 to 2023 marked the ten hottest years on record, highlighting the severity of the issue.

The adverse effects of urban heat disproportionately impact low-income neighbourhoods and marginalised communities, exacerbating economic costs and health risks. There are also substantial regional inequities. For example, East Asia accounted for roughly 20% of heat-related excess deaths globally between 2000 and 2019, totaling over 101,000 fatalities. 

Southeast Asia is among the regions most susceptible to extreme heat. In 2023, the region witnessed a once-in-200-year extreme heat event between April and May, with Thailand experiencing 45.4 degrees on 15 April, being the hottest day in its history. Meanwhile, Laos experienced temperatures of 43.5 degrees. Like everywhere else, the poorest and most disadvantaged groups are easily the most vulnerable demographics to extreme heat in the Southeast Asia region. 

The impact on Singapore 

Despite being the wealthiest country in Southeast Asia, Singapore remains vulnerable to the impacts of extreme heat. Between 1980 and 2020, Singapore’s annual mean temperature increased from 26.9°C to 28.0°C, with 2023 ranking as the fourth hottest year for the city-state. To go even further back, from 1948 to 2016, the annual mean temperatures in Singapore rose at an average rate of 0.25°C per decade, double the world average over the past six decades.

Singapore’s extreme heat is particularly exacerbated by its Urban Heat Island (UHI) effect. The UHI is when buildings, roads, and other infrastructure store heat and also radiate it onto their surrounding environment. The UHI also exacerbates temperature differentials and leads to increased energy consumption and carbon emissions in the form of air conditioning. 

So, what can be done? Singapore has addressed this question through various innovative approaches.

The role of blue-green infrastructure & nature-based solutions 

Despite its relatively small population of 5.7 million, Singapore has emerged as a leader in urban greening and blue-green infrastructure. Singapore's historical emphasis on greenery dates back to Lee Kuan Yew's ‘Garden City’ initiative in 1967. 

Ongoing efforts to increase green coverage, such as the objective to plant one million trees over the next decade, demonstrate Singapore's dedication to mitigating the impacts of extreme heat through the use of nature. The use of nature to resolve issues of climate and environmental degradation is termed nature-based solutions, which the use of urban greenery demonstrates. 

Singapore's four nature reserves safeguard ecosystems, providing vital ecosystem services such as air and water purification, and serving as habitats for native flora and fauna. Nature reserves offer alternative recreational spaces and support biodiversity. This provides the ‘green’ infrastructure, supporting strong urban biodiversity, but also the ‘blue’ infrastructure, being water bodies such as lakes and streams. This has very strong urban resilience outcomes for Singapore, particularly inducing, equitable and widespread heat resilience outcomes for everyday Singaporeans. 

In particular, the Singapore Green Plan 2030 serves as a cutting-edge demonstration of extreme heat management. The Green Plan will reserve an additional 1000 hectares of green space in 10 to 15 years. Likewise, the Skyrise Greenery program has introduced more than 300 hectares of greenery in new urban developments since 200. This demonstrates how buildings themselves can become more green and therefore, radiate less heat. In turn, this mitigates the UHI effect. The Skyrise Greenery Program also provides funding for up to 50% of rooftop greenery installation costs and vertical greenery projects in new buildings. 

The City in Nature plan complements these efforts by expanding the Nature Park Networks with more than 200 hectares of new nature parks by 2030. This in addition to growing the number of Therapeutic Gardens and Nature Playgardens. Under the City in Nature Plan, by 2030, 30 therapeutic gardens will be built across Singapore, providing restorative spaces for those suffering from ADHD and dementia.

Intensifying nature in gardens and parks will bring nature closer to residents, providing opportunities for immersive experiences and promoting health and well-being. 

The role of the built environment in combating heat impacts 

In addition, Singapore possesses the world-leading Landscaping for Urban Spaces and High Rises (LUSH) Scheme. Since 2009, this scheme has introduced over 300ha of greenery in Singapore's built environment. This has successfully driven a regenerative agenda in the architectural practices of Singapore. 

Due to the success of LUSH, in 2014, the LUSH 2.0 programme was created to cover more geographical areas, and from 2017, LUSH 3.0 has built upon the achievements of earlier LUSH phases, supporting the uptake of the greenery in buildings and architecture. 

Vertical greenery on building facades plays a key role in mitigating heat, offering shade, cutting energy bills, and creating a cooler environment for pedestrians. In fact, greening building facades can result in reductions of 10 to 31% in energy cooling loads, and its cooling influence extends up to one metre from the green wall. 

To complement these practices, Singapore is experimenting with cool paints, especially in social housing projects, supporting about 80% of Singapore’s residents. Preliminary findings show that cool paint coatings can reduce ambient temperatures around buildings by up to 2°C.

What role can technology and smart cities play in Singapore's fight against heat impacts? 

Another innovative measure in Singapore has been the Digital Urban Climate Twin (DUCT) initiative, a core component of the Cooling Singapore 2.0 project. This involves developing a ‘Digital Twin’ - in other words, a hypothetical alternative Singapore that can stress test Singapore’s response to future climate change threats. DUCT will integrate computational, regional and micro-scale climate models that have previously been used in Urban Heat Island research to build such scenarios. This can evaluate environmental, land surface, industrial, traffic and building energy factors involved in future heat management scenarios. 

In turn, DUCT enables long-term, evidence-based strategic planning capabilities for Singapore’s extreme heat governance practices, highlighting the important role of technology and smart cities in building policy capacity for Singapore’s extreme heat governance. 

Conclusion - what can we learn from Singapore? 

Singapore serves as a model for innovative governance in combating extreme heat. Governing extreme heat requires a blend of various tools and methods, and Singapore’s blend of nature-based and technological solutions demonstrates this very well. 

As extreme heat becomes a more pressing reality for more of the world’s people, we need to ideate avenues for urban cooling that do not require energy and carbon intensive methods, such as air conditioning. Extreme heat governance is also a social exercise, and Singapore demonstrates various co-benefits to nature-based extreme heat governance, including inclusive spaces and a healthier built environment. 

While some of these solutions may seem obvious, their implementation can be stifled and delayed by complacency and political apathy. Therefore, long-termist, systemic planning practices are paramount in the manifestation of extreme heat solutions in global cities. And yet, time is running out. 

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