Sea Level Change – a Growing Threat to Coastal Cities

by and | Dec 1, 2020 | Asian School of the Environment, Climate Change, Conservation, Earth & Environment, Earth Observatory of Singapore

Photo by Jason Steffan from Pexels

Elementary geography would have taught you that Earth has a lot of water: about 71% of the planet’s surface is covered by it, with 97% of that mass pooled in the oceans and 2% locked up in glaciers and ice caps.

And no wonder, given how essential water is for sustaining life: having enabled fertile land for crops, seafood, and even giving rise to alternative modes of transport. Increasingly though, this compound is becoming a major cause of concern for modern-day coastal cities which presently houses an estimate of up to 40% of the world’s population.

 

Sea Level Changes – What, Why, How

Sea levels have always experienced variability.

There has been climate incidences which have caused significant drops in sea level, but the converse is also true. Today, global mean sea levels are steadily rising and are expected to keep rising until at least 2100. And worse, the global mean sea level has risen 21 – 24 centimeters since 1880, with the last two and a half decades seeing the fastest rise ever recorded.

There are, of course, many factors that could lead to sea level changes. This fluctuation in sea level was once attributed to natural climate variability, which remains a normal course of action experienced by the earth.

Iceberg and Glaciers

Photo by Nick Bondarev from Pexels

However, there is no denying that the human factor is driving the current changes. Exacerbated by humanity’s ever growing carbon emission, global warming has pushed global temperatures upwards, causing rapid melting of the world’s greatest ice sheets – Greenland and  Antarctica – which have contributed a rise of 1.78 centimetres in global mean sea levels since 1990 due to melting of a total of 6.5 trillion tons of ice.

It does not help that the rise in global temperatures have also heated sea waters, causing them to expand in a phenomenon known as thermal expansion.

 

Sea Levels in Singapore

Image of Singapore's seascape

Photo by Ingo Joseph from Pexels

Singapore, a low-lying island-city near the equator is particularly vulnerable to sea level changes.

With around 30% of its landmass less than 5 meters above sea level, the news of rising sea levels has become a blaring alarm for the nation. With limited land, and a dense population, it is absolutely vital for Singapore to be one step ahead of rising sea levels.

To tackle this, the island city state has launched the Singapore National Sea Level Programme, which aims to facilitate research projects that aimed at driving up efforts to reinforce Singapore’s climate defence mechanisms.

 

Two NTU Projects Work to Buff Up Singapore’s Sea Level Defence Mechanism

(Left) Professor Benjamin Horton, (Right) Professor Adam Switzer

(Left) Professor Benjamin Horton, (Right) Associate Professor Adam Switzer

Here at the College of Science, Nanyang Technological University, two research projects under the Asian School of Environment (ASE) and Earth Observatory of Singapore (EOS) have recently been awarded grants under this programme. The first project – led by Associate Professor Adam Switzer – intends to assess potential interactions between sea level changes, coastal hazards, and coastal flood risks. The team will also be testing an extreme sea level (ESL) warning system that makes use of the global navigation system satellite technology. They hope that their findings will provide important inputs for the development of Singapore’s coastal infrastructure.

The second project is led by Professor Benjamin Horton and aims to improve sea level prediction models by studying the history of coastal plants such as mangroves and corals. This will allow the team to map out accurate changes from the past up to the present; the data will then be fed into prediction models, to create better future sea level predictions, allowing for more time to design appropriate defences to face the inevitable.