Commentary: Rising temperatures, fires and floods highlight importance of understanding weather extremes

Commentary: Rising temperatures, fires and floods highlight importance of understanding weather extremes

The day-to-day impact of climate change on our lives are felt through extreme or abnormal weather events, says Adam Switzer from the Asian School of the Environment at NTU.

hot weather dry grass Singapore
Dry weather has turned grass brown by a road in Singapore. (Photo: Chew Hui Min)

SINGAPORE: The year 2019 concluded a decade of consistently rising global temperatures, rapidly retreating ice sheets, and record sea levels – all driven by greenhouse gases produced for the most part by human activities.

Average temperatures for the last five years were the highest on record for most of the planet. Land-based global temperature from January to October 2019 was approximately 1.1 degrees Celsius above the pre-industrial period, according to the World Meteorological Office.

In Singapore, 2019 was our joint hottest year on record, on par with 2016 temperatures.

The island state is heating up at about 0.25 degrees Celsius per decade – twice as fast as the rest of the world, according to the Meteorological Service Singapore (MSS).

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Worse, our planet’s oceans, which act as a buffer by absorbing heat and carbon dioxide, continue to heat up far more quickly than previously thought. Recent research has estimated the oceans are heating up 40 per cent faster on average than estimated five years ago.

At our coast, the rate of sea level rise continues to accelerate primarily due to the melting of ice sheets in Greenland and Antarctica, driven by rising greenhouse gas concentrations. Concentrations of carbon dioxide in the atmosphere hit a record 411.85 parts per million (ppm) in December 2019.

Carbon dioxide we emit into the atmosphere stays there for centuries, and carbon dioxide taken into the ocean stays for even longer, thus locking us into further climate change and global warming.

HOTTER DAYS

Our planet continues to heat up on average. Singapore’s hottest day in 2019 was Apr 17, with 36.4 degrees C measured in Paya Lebar, according to the MSS.

Hot weather, sun in Singapore file photo
A woman with an umbrella on a sunny day in Singapore. (File photo: Gaya Chandramohan)

Our hottest days are likely to get even hotter. Hotter days are not only unpleasant for humans and many animals, but they will likely place greater strain on human health and our health system in Singapore. An increase in the number of days over 36 degrees will place tremendous stress on our vulnerable elderly and those that work outdoors.

Singapore and much of Southeast Asia already experience relatively hot temperatures and high humidity year-round. High humidity means perspiration doesn’t evaporate as quickly placing stress on your body as it is harder to stay cool.

If the temperature continues to rise and humidity remains high then there will likely be an increase in the number of people who experience heat exhaustion and heat stroke.

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This problem is not unique to Singapore. Many other regions across Asia are likely to feel the pressures of extreme heat and its effects on ageing populations and the economically disadvantaged.

ABNORMAL WEATHER EVENTS

While the average climate change indicators continue rising, the day-to-day impact of climate change on our lives are felt through extreme or “abnormal” weather events.

One of the main impact of climate change is erratic rainfall patterns. Such variability in rainfall threatens agriculture and crop yields, which combined with population increase, pose considerable food security challenges to vulnerable countries in the region.

In mid-2019, Thailand saw a significant drop in rice production as reservoirs dried up. Australia, a net exporter of wheat, faced the unique case of needing to seek imports to supply its domestic demand.

Late monsoon fury kills 100 in north India (1)
Patients wade through floodwaters on their way to hospital during heavy monsoon rain in Patna in the northeastern state of Bihar on Sep 28, 2019. (Photo: Sachin Kumar/AFP)

Other events in 2019 also demonstrated the importance of understanding extreme events such as floods and droughts, as much of Asia received abnormally high or low rainfall.

In India, the onset and withdrawal of the Indian Monsoon was delayed, causing a dry spell and water stress in June.

The dry spell was followed by extreme rainfall that generated a series of floods in late July and early August 2019. The floods killed at least 200 people and displaced more than a million.

People were going from having no water in a drought to too much water in floods in the space of a few weeks.

Exceptionally dry conditions prevailed in Asia Pacific over 2019, especially Indonesia and the Mekong basin in the second half, which led to the most significant fire season since 2015, with haze spreading across the region, including Singapore.

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Drought conditions in Australia also highlighted this peril to the world. Much of inland eastern Australia had been experiencing drought through 2017 and 2018, and in 2019, the drought expanded and intensified.

Australia just experienced its worst fire season in recent memory, but as some fires ended, the rains came. Much of fire-ravaged eastern Australia is now experiencing dramatic flood events.

There should be no doubt the Australian fires are linked to climate change. A warmer, dryer atmosphere coupled with prolonged drought were a catastrophe waiting to happen.

The Australian government was warned repeatedly and accurately. The Garnaut Climate Change Review of 2008 said projections of fire weather "suggest that fire seasons will start earlier, end slightly later, and generally be more intense", further stating that "this effect increases over time, but should be directly observable by 2020."

Trees are engulfed in flames as a bushfire spreads in Adaminaby, New South Wales
Trees are engulfed in flames as a bushfire spreads in Adaminaby, New South Wales, Australia, on Jan 9, 2020, in this still image from a video. (Image: Ingleside Rural Fire Service/via REUTERS)

Other climate extremes that made the news several times in 2019 were tropical cyclones or typhoons, with Typhoon Hagibis barely missing Tokyo in October, but still causing severe flooding and significant economic losses.

Toward year-end, the people of the central Philippines experienced yet another damaging typhoon, as Typhoon Phanfone battered the Philippines on Christmas Day, bringing a wet, miserable and terrifying holiday to millions.

With continued warming of our oceans, the future of cyclones and storms remains a topic of considerable debate. Here too, there is much more to do to answer questions about the future of cyclones in our region.

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THE IMPORTANCE OF CLIMATE RESEARCH

Climate researchers are always examining the likelihood of changes in how often extreme weather and climate events will occur and whether or not they will become larger and more damaging.

Unfortunately, our understanding of the dynamic processes in the tropics remains rather poor. We have very little data on the comparative frequency and intensity of past events.

However, the extreme climate events of 2019 have generated a groundswell of activity calling for a new wave of climate impact research. In July 2019, for instance, Malaysia’s Ministry of Water, Land and Natural Resources commissioned a national audit on the water industry in anticipation of the longer droughts expected due to climate change.  

Such research would inform and facilitate efforts by industries and governments to improve the way they interpret and manage risks around extreme climate events.

Swathes of Australian farmland have suffered three or more years of drought
Swathes of Australian farmland have suffered three or more years of drought AFP/Peter PARKS

What we do know is that extreme events are commonly the result of a combination of driving factors. Multiple hazardous events cascade when they act as a series.

For example, droughts can lead to increased risk of wildfires, which then heighten the risk of landslides. This rising risk posed by extreme events is very real in the tropics and Asia’s emerging cities.

We urgently need to dig deeper for detailed investigations of likely changes in storm systems, dry periods, extreme rainfall or heat in the context of a rapidly changing climate.

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CORE ISSUES FOR SINGAPORE’S FUTURE

Climate change and climatic extremes are a core issue for Singapore’s future.  Not only do hotter days strain public health, but prolonged droughts or dry spells will almost certainly stress our water supply.

This will force Singapore to consider further investment in relatively expensive water recycling and desalinisation engineering. 

Moreover, flooding events are all likely to affect the everyday lives of many Singaporeans by disrupting transport and business.

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Against the backdrop of rising sea levels, Singapore faces an increased risk of compound flooding as flood waters reach our coast.

In his Budget 2020 speech, Finance Minister Heng Swee Keat announced a new Coastal and Flood Protection fund with an initial injection of S$5 billion. Being that climate change adaptation might cost S$100 billion or more over 100 years, Singapore is beginning to set aside resources for it.

As we keep an eye on climate change, it's crucial that we understand how it can manifest as extreme weather, with adverse impact on Singapore and the region.

Adam Switzer is the Associate Chair (Academic) of the Asian School of the Environment and a Principal Investigator in the Earth Observatory of Singapore at Nanyang Technological University (NTU).

Source: CNA/el

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