Box Story: Cooling Singapore

With global temperatures on the rise due to climate change, Singapore is confronting an increasingly formidable challenge. As a highly dense, tropical city-state, rising temperatures and urban heat can undermine thermal comfort and health, impacting overall liveability for the city’s residents. The Cooling Singapore project was launched in 2017 in response to the gravity of the situation. Supported by the National Research Foundation (NRF) under the Prime Minister’s Office, this multi-disciplinary project drew upon the collaborative efforts of researchers from institutions including the Singapore–ETH Centre, Singapore–MIT (Massachusetts Institute of Technology) Alliance for Research and Technology, TUMCREATE (Technical University of Munich), Singapore Management University, National University of Singapore, and the Cambridge Centre for Advanced Research and Education in Singapore.

Among the innovative solutions devised was the Digital Urban Climate Twin (DUCT), specifically crafted to address the complexities of understanding the causes of urban heat in Singapore. The project aims to utilise DUCT to evaluate scenarios for future climate analysis, which will help in putting together urban design guidelines and informing strategies to tackle future impacts of climate change.

Scenarios that can be simulated using DUCT to assess impacts of various heat management strategies (Cooling Singapore 2.0 project by the Singapore ETH Centre)

Assessing the Urban Heat Island Effect and Outdoor Thermal Comfort

To construct DUCT, the project team focused on identifying suitable metrics and tools for assessing the UHI effect and outdoor thermal comfort (OTC). They then compiled an extensive catalogue of potential heat mitigation measures and pinpointed key knowledge and technology gaps to guide future research and development endeavours. Subsequently, the researchers evaluated the efficacy of various cooling strategies and devised a decision support system to assess the OTC associated with different approaches. Additionally, a set of climate-responsive urban design guidelines was formulated, tailored to Singapore’s unique context. Throughout the investigation, the researchers observed a pronounced UHI effect, resulting in temperature differentials reaching up to 7°C across Singapore. The projections indicate that a warming planet could further elevate temperatures by 1.4–4.6°C by the year 2100.

DUCT simulations show impacts of (A)integrating vegetation, (B)improving wind potential, (C)mitigating heat wave (D)reducing heat emissions by increasing electric vehicle sharing to create (E)an overall comparison (Cooling Singapore 2.0 project)

Constructing the Digital Urban Climate Twin

The development of the DUCT system for Singapore necessitated the integration of diverse data sources, including land use data, anthropogenic heat profiles, meteorological data and urban geometry. Leveraging these data sources, DUCT possesses the capability to simulate the effects of the UHI, OTC and climate scenarios, furnishing valuable insights for future climate analysis. The system enables the testing of various cooling measures, including innovative transportation systems, advanced building technologies, vegetation typologies, materials for buildings and pavements, and climate-sensitive urban design solutions, across spatial scales. This simulation capability empowers the formulation of targeted urban design guidelines to address anticipated climate developments. In addition to computer-based software, a DUCT Explorer app is being developed in close collaboration with Singapore government agencies to ensure its relevance.

Conclusion

The Cooling Singapore project aims to equip relevant planning agencies with the tools needed to devise effective solutions to combat rising temperatures. By using DUCT to simulate climate scenarios and test various cooling measures, policymakers are able to implement more targeted interventions, such as integrating green infrastructure and modifying building design to mitigate the adverse effects of urban heat, and safeguard the thermal comfort and well-being of residents in the city.