CNA's 'Killer Heat' episode of Why it Matters explores the effects of rising temperatures in Singapore

The hot weather we’re experiencing might not be just temporary or seasonal thing. The island is actually heating up at twice the speed of the rest of the world, according to the Meteorological Service Singapore (MSS), and as quoted by PM Lee in his National Day Rally speech. Singapore is roughly 1° hotter today than it was in the 1950s. Exploring this rather pertinent issue, episode 8 of Channel NewsAsia’s (CNA's) Why it Matters programme sees host Joshua Lim speaking to experts to learn more about how global warming is affecting the island of Singapore. The episode is called Killer Heat. One Dr Muhammad Eeqmal Hassim, a senior research scientist with the MSS Centre for Climate Research Singapore warned that the country’s maximum daily temperature is anticipated to reach up to 35-37 °Celsius in the next 80 years in 2100 if carbon emissions remain unchanged. But in Singapore, this is worsened by the fact that the humidity is high all year round, which would lead to potentially deadly consequences. “When temperature and humidity get high enough, our bodies struggle to cope,” explain Dr Eeqmal. “We get higher heat stress levels. It can actually be quite lethal for us.” Speaking to Professor Matthias Roth from the National University of Singapore’s Department of Geography, Mr Lim finds out that the rising temperatures are attributed to global warming and the Urban Heat Island (UHI). The UHI happens when the heat is trapped by buildings and roads, making urban areas hotter than rural ones. In the programme, the temperate recorded at the rural Lim Chu Chang area of farms and forests was about 24.8 °Celsius while the temperate at the heavily developed Orchard Road on the same night was four degrees warmer, at 29.1 °Celsius. The irony here is that a major factor that contributes to the build-up of heat in urban are is the thing we use most to keep ourselves cool – air-conditioners. Every office building, housing block, and mall in Singapore rely on air-conditioners which end up released a lot of hot air into the atmosphere. The hot air is subsequently trapped in urban surfaces which in turn causes external temperatures to rise even further. Professor Gerhard Schmitt, head of a research team called “Cooling Singapore” at the Singapore-ETH Centre, explained the problem with stacked air-conditioning units: “The bottom one is ejecting heat to the outside, but this heat is then sucked in by the next one, and the next one and the next. The higher you go, the higher the temperature that comes out.” So the higher the house or office, the more they need to cool the temperature using air-conditioners and therefore the higher their electricity bill would be.

What does global warming mean for Singapore?

The episode also explored the effects that rising temperatures would have in Singapore. The main problem is high humidity which, when combined with high heat, can have deadly consequences on the human body. In highly humid weathers, sweat doesn’t evaporate as quickly as it does in drier places. This means that the human body will have to expend more energy to stay cool in warm weather, leading to exhaustion and worse, a heat stroke. Heatstrokes can happen when your body’s core temperature goes beyond 40 °Celsius. At that point, your body won't be able to effectively and sufficiently expel heat. Severe heat strokes can lead to organ damage and are sometimes fatal. In Singapore, the relative humidity ranges between 90% in the morning to about 60% in the afternoon if it doesn’t rain, says the MSS. When it does rain, and for a long period, then relative humidity often reaches 100%. So on the urban island of Singapore, the risk of heat strokes is very real.

What can we do?

On whether anything can be done to stop this increase in temperature, Dr Roth talked about the importance of Singapore’s remaining forests. He said that it is crucial to leave those forests untouched and ensure it is protected from future development. We all know that forests are the Earth’s lungs, but they’re also the Earth’s natural, sustainable air-conditioners. Without them, we're only making harder for ourselves to reduce or at least mitigate the rising temperatures. On whether rooftop gardens and vertical urban gardens or even green facades on buildings would help mitigate rising temperatures, Dr Roth isn’t confident it will make much of a difference. “The research that has not really shown that greening initiatives have a beneficial effect on the local microclimate in terms of reducing the actual urban heat island effect,” he said. The UN released a paper in 2018 saying that we had only 12 years to do what we can to cut carbon emissions by half or risk heading into a climate catastrophe. On that note, Dr Schmitt said that every person in Singapore can contribute to fighting global warming as “every individual in Singapore controls about 30% of all the energy consumed or produced here”. Some steps individuals can take include switching to public transport. Also, turning up the air-conditioning by just 1 °Celsius can reduce your air-con bill by as much as 5%. But even after all that, people in Singapore might just have to get used to high temperatures. In places where fatal heat strokes are reported, it’s usually where temperature increases were sudden and drastic. Whereas in Singapore temparatures are rising more gradually, which allows people more of a chance to adapt to the heat. However, one Dr Li did warn that even if the high temperature doesn’t kill you, it can significant affect your life. So there is still cause for concern. In his National Day Rally speech this year, PM Lee Hsien Loong spent some time talking about climate change, calling it "one of the gravest challenges facing humankind". He then said that Singapore will need about S$100 billion to tackle the issue of climate change and rising sea levels effectively. Some of the measures mentioned include adding one more pump house at Marina Barrage, regaining offshore islands on the eastern coast of Singapore and producing polders.