How Singapore Uses Science to Stay Cool

If you look at a thermal image of a city and then compare it with a vegetation map, you will find that where there is vegetation, the temperature is lower. This is because things like asphalt, concrete, and tile roofs absorb more heat from the sun than trees. This is the urban heat island effect and explains the higher temperatures in cities, often by several degrees compared to their surroundings. It is becoming a huge risk to human health as growing urban populations exacerbate the warming effects of climate change. Heat waves kill more people than any other extreme weather event, more than tornadoes, hurricanes and even floods.

That is why a group of researchers in Singapore is studying mitigation strategies for urban heat islands. The government-backed project called Cooling Singapore is now in the process of combining everything they have learned to create a digital tool that can help cities around the world, starting with Singapore. In Singapore, near the equator, temperatures regularly exceed 32 degrees Celsius or 90 degrees Fahrenheit. And the city structures only make it worse. And that is also the case in Singapore, which is basically a concrete jungle, a more urbanized and more developed city. And even in Singapore what we have is a situation where there is a temperature difference of 7 degrees Celsius between the most urbanized areas and the most rural areas.

The government has taken drastic measures to keep temperatures down. This is Gardens by the Bay, an award-winning park. And inside this greenhouse it is a pleasant 24 degrees. That's because the dome, along with two dozen nearby towers filled with thousands of people, is

cool

ed by what is likely the largest underground district

cool

ing system in the world. It

uses

a large central plant that cools the water and then channels it to banks, residential towers, an exhibition centre, shopping malls and the city's iconic Marina Bay Sands hotel and casino complex. So, one of the biggest advantages of using this system for buildings is that they can save 40% in terms of electricity usage compared to traditional air conditioners.

And since Singapore relies on natural gas for most of its energy, this new system means emissions savings equivalent to removing 10,000 cars from the city's roads. This has big implications for the rest of the world. If things continue as they are, more than a third of the world's electricity could end up being used to cool buildings and vehicles by 2050. As the world warms, the need for air conditioning and refrigerators increases. , For example. And the more people buy these appliances, the more energy they use and release more heat, exacerbating climate change. It is a vicious circle. And that's why, since 2017, Cooling Singapore researchers have been identifying design solutions that reduce our need for so much cold air in the first place.

One thing that many cities have in common is the importance of greenery. This is a very important measure to mitigate urban heat due to the shading effect, of course, and the profound psychological effects of vegetation. And also due to the possible evaporative cooling effect of the vegetation. Vegetation can, of course, be on the ground floor in the form of trees and bushes. And you can walk under them. This is the so-called canopy layer that forms the vegetation above us. But vegetation can also climb the facades of buildings and can reach the roof of buildings. Fortunately, Singapore has been striving for the garden city feel for quite some time.

It was a vision initially introduced by then Prime Minister Lee Kuan Yew in 1967 to make life more pleasant for people. And today, Singapore is one of the greenest cities in the world in terms of urban greenery. Kampung Admiralty, a community center containing health facilities and social spaces, now offers more green space than the land it was originally built on. It is topped by a roof of stepped terraces covered with local plants, which functions as a community park, and a community park in the center containing agricultural plots for residents to tend. Parkroyal on Pickering was designed as a garden hotel which doubled the green growth potential of its site.

There are now 15,000 meters of raised gardens, reflecting pools, waterfalls, terraces with planters and green walls. And the government has big plans too. In fact, Singapore has a plan to plant 1 million trees and add more green spaces in the next 10 years. It's actually a combination of one thing to reduce the urban heat island effect. But, on the other hand, it is also about getting people more connected to nature. But it's not enough. The city-state has still warmed twice as fast as the global average over the past six decades. That's why Cooling Singapore has developed a catalog of other possible heat mitigation measures.

When trying to mitigate the urban heat island effect in a city or any building, including a town, the first place to start is by protecting the windows. You have to keep clear areas so that the wind can cross them. Water at a certain depth can act as a very good thermal buffer. If you have to build heavy buildings, such as skyscrapers, you can at least make the surface and façade less heavy. And you can protect it from direct sun penetration. We have to ensure that in the medium and long term there are no combustion engines in the city.

Ideally, electricity production should take place outside the city. And you bring only clean electricity to the city. At least energy use in the city can be minimized. And you can begin to gradually convert the roofs, the facades of the city, into renewable energy production areas. Unfortunately, in Singapore this is a limited option. But in the long term, it could produce up to 20% to 25% of the energy needed in Singapore. If all the roofs and areas of the buildings, of the buildings and of the facades were used to do that. With so many different ideas, Cooling Singapore is also designing a virtual model of the city to test them out.

It's called the Digital Urban Climate Twin, or DUCT, and it will calculate how each element of the city's design will affect the urban heat island effect. This means that we not only digitally model the geometry of buildings, but we also model transportation, insulation, temperature, radiation from the sun, weather, local weather, local climate, and even microclimate. of the city, the water, the movement of people in the city. We can invent scenarios. We can design scenarios and test them before building them. And if they are tested very well and we are sure that they will work, then we can start building them and making them a reality.

Singapore will use this new tool to determine what actions it should take next. And the model can be applied to any city, whether it needs to keep heat outside or inside, which will ultimately save energy, curb climate change and improve our quality of life. So this is something that Singapore will be able to export, perhaps even alongside the urban development systems it already has. Singapore is one of the few cities in the world that really combined this scientific approach with a very well-established urban redesign and urban design approach. Through its agencies and the combination of its agencies, it has achieved a lot in the past.

If the scientific path continues and the combination with other knowledge that already exists in the city, we believe that in the future it will be a very comfortable and very livable city, even more than today.