What this lesson teaches
I can explain how climate change affects Singapore and the challenges and opportunities it brings.
Syllabus K329, Topic 5.2, Key Question 1. How might climate change affect Singapore?
Make a guess
Singapore builds a higher sea wall. Will it stop the flash floods that happen after very heavy rain inland?
- Yes, if the wall is tall enough to hold the sea back.
- No. Those floods come from drains that cannot cope.
- No, because flash floods do not happen in Singapore.
- Yes, because Singapore's floods come from the sea.
Show the answer
No. Those floods come from drains that cannot cope.
Coastal floods and inland floods are different. A sea wall holds back the sea, but heavy rain far from the coast needs drainage and space for water.
Climate change reaches Singapore through its coasts, streets, ecosystems and the overseas supplies it depends on.
Rising sea level gives tides and storm surges a higher starting point, so coastal floods become more likely. Heavy rain causes floods inland when drains cannot cope. These are two different kinds of flood. A sea wall cannot fix a drainage problem.
Global warming raises temperatures everywhere. Cities add extra heat: roads and buildings store heat, and there are fewer plants. This urban heat island effect is separate from global warming, but adds to it. Hot, humid air makes it hard for the body to cool down. Heat and rain also affect where mosquitoes breed, which can spread diseases like dengue, alongside other factors such as how well breeding sites are removed.
Heat can harm sensitive plants and animals. Dry spells reduce rain-fed water supply. Crop failures and transport problems overseas can cut Singapore's food imports or raise prices. So Singapore's climate risks reach beyond its own island.
- Coastal flooding
- Rising seas raise tides and storm surges.
- Urban heat island
- Cities are hotter than their surroundings.
- Imported risk
- Overseas crop losses can raise food prices here.
Step by step
Climate changes
Sea level, heat and rainfall shift.
Local conditions matter
Height, drains, surfaces and trade links shape the effects.
People face different risks
Shade, cooling, health and supplies affect coping.
Real examples to use
Rising temperatures
Singapore's annual mean temperature has risen by about 0.25 degrees Celsius per decade since 1948, faster than the global average, partly because of the urban heat island effect.
Flash floods on Orchard Road, 2010
Heavy rain flooded shops and basements at Liat Towers, showing how intense storms can overwhelm drains in a built-up city.
Low-lying land (NCCS)
About 30% of Singapore's land is less than 5 m above mean sea level, so rising seas and storm surges threaten a large share of the island.
Worked example: Two people, one city
An outdoor worker and an office worker in air-conditioning face very different heat on the same day. Age, health, shade and rest breaks also matter. One city-wide temperature cannot describe everyone's risk.
Watch out for this
Climate change creates the urban heat island.
Cities create their own heat island. Global warming adds to it by raising the background temperature.
Check your understanding
Which statement is correct?
- A sea wall prevents floods from heavy rain inland as well.
- Urban heat islands and global warming are the same process.
- Global warming can make an urban heat island hotter.
Show the answer
Global warming can make an urban heat island hotter.
Yes. The two effects add together.
Check your understanding
Why can a sea wall alone not prevent flash floods on Orchard Road?
- Flash floods come from heavy rain overwhelming drains inland.
- Orchard Road is below sea level, so water flows in from the coast.
- Sea walls let water seep under them at high tide.
Show the answer
Flash floods come from heavy rain overwhelming drains inland.
Different flood types need different responses.