CNA Explains: What can we do about the extreme heat across Asia - including in Singapore? (2024)

Much of Asia - including Southeast Asia - has been baking under high temperatures, prompting school closures as well as authorities across the region to issue health warnings amid heat-related concerns.

The months of March, April and May are typically the hottest and driest in the region, but conditions this year have been worsened by the El Nino weather phenomenon.

What is happening across Asia?

In the Philippines, in-person classes have been suspended for two days due to the extreme heat, forcing students to switch to remote learning.

More than 47,000 public schools are affected. Many have no air-conditioning, leaving students to swelter in poorly ventilated classrooms.

In Thailand, soaring temperatures have led to a record surge in power usage over the weekend. Bangkok's heat index – which measures what a temperature feels like to the human body, taking into account relative humidity – crossed 52 degrees Celsius, and was deemed “very dangerous”.

The Thai government said at least 30 people have died due to the hot weather this year, compared with 37 heat-related deaths in the whole of last year.

In Cambodia, Myanmar and Vietnam, forecasters warned that mercury levels could exceed 40 degrees Celsius in the coming days.

Meanwhile in India, some people are queuing up in the sweltering heat to vote in the world's largest election.

Several states have recorded temperatures as high as 42 degrees Celsius, and the severe conditions are likely to continue for the next few days.

In Bangladesh, which is facing its longest heatwave in 75 years, schools have reopened with millions of students returning, despite the lingering heat that prompted a nationwide classroom shutdown order last weekend.

What is causing the sweltering heat?

The high temperatures recorded in various parts of Asia is a result of climate change and the El Nino weather pattern, which warms ocean waters when it occurs typically every two to seven years, said experts.

Professor Benjamin Horton, director of the Earth Observatory of Singapore, said the underlying cause of extreme weather around the planet is human-induced climate change.

“Every year when we get to May and June, if we're in an El Nino phase, human-induced climate change will cause the temperatures to always approach records,” he told CNA938 on Monday (Apr 29).

“The climate community has been warning about this for several years … What needs to happen now is that we need our governments (and) our private enterprises to think about this problem really seriously and urgently, to try and keep people safe.”

What about Singapore?

The situation in Singapore is not quite the same as the rest of the region due to its location on the equator, said Prof Horton.

“So when you move further north or south of the equator, you have stronger seasonal extremes. We know in Singapore, our temperature doesn't vary that much during the year,” he added.

“We're surrounded by ocean water on all sides, and so therefore, that is a cooling effect as well.”

However, Singapore has to prepare for extreme weather conditions, said observers.

This comes as the island is warming up twice as fast as the rest of the world, at 0.25 degrees Celsius per decade, according to the Meteorological Service Singapore.

In tropical Singapore, the mercury hit 37 degrees Celsius on May 13 last year, equalling a 40-year record for the highest daily maximum temperature.

“Unfortunately here in Singapore, when we have periods of cloudless skies in the middle of the afternoon, you're going to have very, very hot temperatures,” said Prof Horton.

“Therefore, the population needs to be prepared for that, being hydrated, being able to artificially cool themselves with air conditioning.”

Singapore’s greening efforts have helped to make some areas cooler and more comfortable.

“The greening of Singapore causes very localised changes,” Prof Horton said. “So if you could increase the vegetation … within the city, you would find a natural cooling effect.”

What does the heat do to our bodies, and who is at greater risk?

Hot days are not only uncomfortable but can also be unhealthy, said experts.

High temperatures have an impact on the body, which has an average temperature of about 36.5 degrees Celsius.

The body sweats to stay cool, but if that water loss is not replenished, dehydration will occur. The heart is also forced to pump harder as it tries to regulate the body's temperature.

“We do have thresholds, physiological limits to heat,” said environment, climate and global health professor Kathryn Bowen from the University of Melbourne.

“We know that the higher the temperature gets, the more our bodies have to work to be able to cope with that heat.”

However, the human body cannot maintain high levels of internal heat for long periods.

“Part of the issue that we are seeing now is that overnight temperatures aren't dropping, so they're not allowing our bodies to cool and recover after periods of intense heat. So that's really one of the biggest challenges we have ahead of us,” Prof Bowen, who is deputy director of the Melbourne Climate Futures research institute, told CNA’s Asia First on Monday.

“If we don't see (overnight temperatures) dropping, that will really be catastrophic for human health and wellbeing.”

Heat exhaustion is a common risk when the body overheats, and can include dizziness and headaches.

Prolonged exposure to intense heat can also escalate to heatstroke, when the body's core temperature goes above 40.6 degrees Celsius. The medical emergency, marked by symptoms such as rapid breathing, confusion or seizures, can cause long-term organ damage and death.

Some groups are at a greater risk of extreme heat problems, including young children, seniors, athletes, and individuals such as outdoor workers and the homeless who are more exposed to weather conditions.

The heat could also affect people with pre-existing health conditions such as respiratory and cardiovascular diseases.

The countries that have seen warmer temperatures in recent weeks often have to deal with added problems, including air pollution in many of their urban areas, said Prof Horton.

Besides physical health, the prolonged duration of heat can affect the mental and emotional aspects.

Heat-related conditions have “massive ramifications” for the healthcare system, particularly in poorer countries that do not have enough medical facilities to treat a large influx of patients, Prof Bowen said.

He added: “We know that with the projections around the increase in intensity and frequency of heatwave events, we must ensure that our healthcare facilities are prepared.”

How can we prepare for a future of higher temperatures?

Studies have shown that climate change is causing heatwaves to become longer, more frequent and more intense.

Prof Horton said some of the effects of human-induced climate change are not irreversible.

“We caused it; we can solve it. We have all the technology to do that in terms of renewable energy, in terms of protecting our nature for carbon capture and storage. So we have the power within ourselves to reverse the impacts of climate change,” he added.

“Unfortunately, though, because of the past and current emissions, we're going to have to deal with these types of temperatures for the next decade or so. If we were to take the right actions, our temperatures can be stabilised.”

Prof Horton said developing a warning system is essential because the extreme heat can be deadly for the young, the elderly, and people with pre-existing medical conditions.

In particular, adapting the environment to handle such climate abnormalities is crucial. This includes reducing the urban heat island effect – a phenomenon where urban areas, which are more built-up and densely populated, get warmer than rural areas.

Some of the ways to tackle this effect include having more open spaces around buildings and using cooler materials such as white roofs.

In Singapore, studies have shown temperature differences of up to 7 degrees Celsius between urban and less built-up areas.

Prof Bowen said the world must rapidly reduce greenhouse gas emissions, and that richer countries have to take the lead in doing so.

“We must crucially ramp up our mitigation, so that we are not living in a world 50 years from now (where) we'll see three or four times the heatwave events that we are currently seeing now,” she added.