SINGAPORE: The average sea level has risen 14cm from “pre-1970 levels” for Singapore, said the Meteorological Service Singapore (MSS) in its 2019 Annual Climate Assessment Report released on Monday (Mar 23).
"The sea level changes described in the (report) are based on tide gauge records available since 1970s at various locations in Singapore. We have therefore considered this time frame as our period of interest,” explained Dr Hindumathi Palanisamy, a senior research scientist with MSS.
Since the 1970s, Sembawang, Sultan Shoal and Raffles Lighthouse have shown sea level rise rates of about 2.12mm per year, about 2.78mm per year and about 3.55mm per year respectively, said MSS, which has led to an average sea level in Singapore today of 140mm above pre-1970 levels.
Dr Hindumathi said that Singapore’s average rate of sea level rise has been around 2.8mm per year since the 1970s.
Global warming has resulted in the heating up of oceans and the loss of ice mass from the Greenland and Antarctica ice sheets, added MSS.
“Warming oceans cause sea level to rise. Similarly, melting of glaciers, Greenland and Antarctica ice sheets ultimately reach the ocean thus further increasing sea level,” MSS said.
“Thus, in addition to extreme events such as heat waves, floods, droughts, cyclones ... sea level rise is one of the most severe impacts of climate change posing a major threat especially to highly populated low-lying coastal regions and island nations of the world.”
This means that Singapore is “highly vulnerable,” explained MSS.
On average, the 20th century global sea level has been rising at a rate of 1.2mm to 1.9mm per year, said MSS.
“Since 1993, which marks the beginning of high precision (satellite-based) altimetry records, the global average sea level has risen at a rate of about 3.24mm per year and has reached its highest level of about 90mm above the 1993’s level in 2019,” it added.
“Sea level rise is not uniform and varies regionally and at different time scales. In fact, in a number of regions, sea level trends deviate significantly from the global mean.”
Various factors such as ocean dynamics, local land motion and gravitational changes affect sea level rise, explained Dr Hindumathi.
“The influence of these factors determines whether rates of local sea level change are higher or lower than the global average. For example, the impact of Greenland and Antarctic ice sheets on sea level rise will be felt more near the equator than anywhere else due to the weakening of gravitational pull at the poles arising from ice sheet melt,” she said.
“As a result, the water from the melt is drawn towards the equator thereby making the equatorial regions more vulnerable (about 30 per cent more) than any other region.”
The threat of sea level rise on Singapore was emphasised by Prime Minister Lee Hsien Loong at last year’s National Day Rally.
In his speech, Mr Lee warned that significant areas of Singapore are 4m above mean sea level or lower, and they will increasingly be at risk of going underwater when sea levels rise.
Calling climate change one of the gravest challenges the human race faces, Mr Lee added that it could take S$100 billion over 100 years to protect Singapore.
“If we only have 10 years to solve the problem, we won’t have the time or resources to do it. But because this is a 50 to 100-year problem, we can implement a 50 to 100-year solution,” he said.
Additional measures would include the need to build coastal defences, he pointed out. Solutions include the construction of “polders”, which is land that is reclaimed from the sea.
In his Budget speech in February, Finance Minister Heng Swee Keat, also announced a new Coastal and Flood Protection fund with an initial injection of S$5 billion by the Government.
The fund will be topped up whenever Singapore’s fiscal situation allows for it, said Mr Heng.
“(The Prime Minister) mentioned at the National Day Rally last year that climate change adaption might cost S$100 billion or more over 100 years,” said Mr Heng. “This is a major fiscal outlay in the coming years – so it is right and prudent that we set aside resources for this.”