Protecting Singapore against rising sea levels will cost S$100 billion or more over the next 50 to 100 years.

Threats to Singapore caused by climate change and ways to mitigate its effects within our budget were outlined by Prime Minister Lee Hsien Loong during the 2019 National Day Rally on Sunday, Aug. 18.

Here are all the facts.

Treated with utmost seriousness

• PM Lee noted that both climate change defences and the Singapore Armed Forces (SAF) should be treated “with utmost seriousness”, as they represent matters of "life and death".

• “Everything else must bend at the knee to safeguard the existence of our island nation,” PM Lee said.

• The difference between the SAF and climate change, is that climate change might not be deterred.

Sea levels will rise for sure

• Sea levels will rise for sure, and it is a matter of whether it arrives a few decades sooner or later.

• Coastal defences are needed because significant areas of Singapore are 4 metres above mean sea level or lower.

• These areas will be increasingly at risk of going underwater when sea levels rise.

• The segment stretching from East Coast to the city is critical.

Marina Barrage's purpose for downtown Singapore

• Currently, rain falling in the city area can drain into Marina Reservoir.

• The Pump House at Marina Barrage then pumps water out of Marina Reservoir into the sea when it rains heavily.

• A second pump house will need to be built at the opposite end of the Barrage.

Other countries have solutions

• Singapore has looked The Netherlands for inspiration to deal with the eastern coastlines.

• The Dutch uses “polders”, which are land that has been reclaimed from the sea, and dykes to keep the land dry.

• Another option is to reclaim a series of islands offshore from Marina East to Changi, connect them up with barrages and create a reservoir, similar to Marina Reservoir.

Options are still open.

Budget must factor in long-term costs

• Singapore must "maintain a stable budget year after year" and "do it over many years and several generations”, PM Lee said.

• A period of 10 years is not enough to solve the problem as there is not enough time and resources.

• But PM Lee said it can be done when the horizon is stretched: "But because this is a 50- to 100-year problem, we can implement a 50- to 100-year solution to this problem."

Singapore must reduce waste

• Singapore must reduce the amount of waste it produces.

• The usual culprits are excessive packaging, food waste, and electronic waste.

• The Pulau Semakau landfill is filled with trash and incinerated ash, and will eventually fill up to become “Bukit Semakau” or “Gunung Semakau”, PM Lee joked, saying a hill or mountain will subsequently be formed at this rate.

• PM Lee said: “We must make this effort. Otherwise, one day, our children and grandchildren will be ashamed of what our generation did not do.”