Is Singapore's pleasant chill a hint of coming climate change?

In the early weeks of January, unusually cool weather descended on Singapore and its neighbouring countries. While the dip in temperatures came with heavy downpours of rain, it was a change Jessie Tay embraced. The marketing executive, 32, took the opportunity to break out her cosy knits and hoodies, which she once reserved for autumn holidays.

"For once, we can leave our homes and not be plastered in sweat by the time we get to the bus stop or railway station," Tay said. "It was raining badly, but at least that came with great weather."

In a region usually plagued by sweltering heat, cooler weather prevailed in January. Temperatures fell as low as 19 degrees Celsius (66 degrees Fahrenheit) in Manila, while Bangkok recorded a record low of 16 degrees.

Get the latest insights and analysis from our Global Impact newsletter on the big stories originating in China.

But while Tay and many others embraced the uncharacteristic chill, climate experts warned it could be the first hint of unfolding climate change in the region.

"The slightly cooler air delivers lots of moisture, which can lead to heavy rainfall and flooding, said Matthew Ashfold, head of the environmental and geographical sciences school at the University of Nottingham Malaysia.

At particular risk, he said, were the east coast states of peninsular Malaysia, "which typically receive lots of rainfall when cold air outbreaks occur".

Southeast Asia typically experiences rainy conditions during the wet phase of the northeast monsoon season from December to January, said Benjamin P. Horton, director of the Earth Observatory of Singapore at Nanyang Technological University. At times, a monsoon surge occurs, where sudden increases in wind speed bring cold air from the north to the equatorial region, which most of Southeast Asia lies within, causing cooler weather, he explained.

Residents caught in a downpour in Bekasi, on the outskirts of Jakarta, on Monday. Indonesia is expected to bear the brunt of worsening climate conditions. Photo: AFP

But the chillier-than-normal temperatures and torrential downpours were also occurring because of the weather phenomenon known as La Nina, which typically peaks at this time of year, said Gerry Bagtasa, a professor with the Institute of Environmental Science and Meteorology at the University of the Philippines.

La Nina is the cooler phase of a climate cycle called El Nino Southern Oscillation, or Enso, with the warming phase known as El Nino.

"There may be other factors that may oppose or exacerbate the effects of La Nina, but increased rainfall in the region is practically" its signature, he said.

The successive tropical cyclones in the Philippines last November - several of which morphed into intense typhoons - were partly caused by La Nina, Bagtasa said. The country saw 22 tropical cyclones last year, with the strongest of the year being Typhoon Goni on November 1.

An El Nino episode intensifies a cyclone and causes it to track northward to East Asia, while a La Nina event would cause the cyclone to form east of the Philippines, he said.

In Malaysia, days of torrential rain that started on January 1 triggered widespread flooding, with nearly 50,000 people escaping floodwaters in the Malaysian states of Kelantan, Terengganu, Penang and Johor. At least six people died in the flooding.

Indonesia's start to the new year has been rife with landslides and floods caused by heavy rain. The worst flooding in 50 years hit South Kalimantan, a province on Borneo Island, on January 12, with more than 400,000 residents affected and 20 deaths reported. Two landslides occurred in Sumedang, West Java, on January 9, killing at least 32.

CLIMATE CHANGE REALITIES

Tracing the causes of such natural disasters can be complex. Adam Switzer, a colleague of Horton's at the Earth Observatory of Singapore, said they could not yet be directly linked to climate change.

Places like South Kalimantan and Sumedang are also less directly affected by cold air surges, and normally experience heavy rains in January with or without additional weather phenomena, Ashfold said.

And in Malaysia, other factors like deforestation could be at play in triggering floods, Ashfold added.

"Forested land absorbs and holds more water, so less water runs off across the surface to cause flooding. Malaysia has lost forest, and that could enhance flood risk," he said.

But some experts cautioned that January's cool weather could give a false idea of the reality of climate change, leading to misconceptions that its impact is less destructive than imagined.

"These cold spells in the weather for Singapore have been used by climate contrarians to question the reality of human-induced climate change," Horton said. "Such misinformation obscures the work scientists are doing to figure out just how climate changes."

Bagtasa, however, said that since the world had just experienced the hottest year on record, people were more open to the possibility that recent weather events were due to climate change.

The past decade of 2010 to 2019 was the hottest ever recorded, and 2020 was the warmest year on record, edging out 2016 by a fraction of a degree - even with the cooling influence from La Nina that peaked last November.

Ashfold said most Malaysians were indeed concerned about climate change, citing a 2020 Pew Research Centre survey where 73 per cent of respondents prioritised environmental protection over economic growth.

But he added: "It may not be a high enough priority to affect people's daily behaviour in a significant way - for example in motivating people to reduce emissions from their daily activities.

"I am, however, optimistic that many younger Malaysians are grasping how crucial addressing climate change is for a healthy future in Malaysia - I don't believe the few cooler days in the past month would reduce their concerns, especially given the associated flooding problems," he said.

WORSE TO COME?

Southeast Asia will not be spared from the ineluctable consequences of climate change, particularly lower-income countries, as highlighted in a McKinsey Global Institute report last year.

By 2050, the region could see annual GDP shrinkage of 8 to 13 per cent as it gets hotter and more humid, with countries that are more reliant on outdoor labour especially affected.

More frequent and intense rainfall is expected to affect the region by the same year, with Indonesia in particular expected to feel the brunt.

"The latest batch of extreme weather events, including cold temperatures and heavy rainfall, suggests that the climate is entering uncharted territory," Horton said. "Weather will increasingly fall outside the historical norm."

And as the Earth gets hotter, such extreme events will occur more frequently.

"The reason is simple: the Earth is getting warmer, with significantly more moisture in the atmosphere. As the atmosphere gets warmer, it can hold more moisture. The intensity of downpours, and therefore the risk of floods, depends in part on how much water the air can hold at a given time," said Horton.

Evidence showed that El Nino events were getting more frequent, too, said Bagtasa.

"The warming effect of El Nino is much more than the cooling effect of La Nina," he said. "So though there's a possibility for more cooler winter seasons, it will be eclipsed by a warmer overall temperature."

This article originally appeared on the South China Morning Post (SCMP).

Copyright (c) 2021. South China Morning Post Publishers Ltd. All rights reserved.