Sea level rise – what’s the big deal?
by China Water Risk 20 October, 2020
We’ve put sea level rise to the back of the to-do list – labeling it with “not a big deal” and “plenty of time to deal with this”. But is there? This month we deep dive into rising seas – how high will they rise? How much will Bangkok sink by? What about typhoons in Guangdong and Mekong, will their paths change? Should we rethink typhoon randomness in evaluating impacts? We turn to global and local experts for answers to find that it’s time to prioritise our rising seas.
Sea level rise or SLR (no not an expensive camera) is arguably one of the most well-known impacts of climate change. Everyone knows that seas will rise and islands will be impacted, the Maldives and large parts of Bangladesh as well as Florida will vanish, swallowed up by our seas. Asia is clearly vulnerable, so why is it not THE topic of conversation?
We know you have been occupied with the pandemic, so we have summed it up in three reasons to prioritise SLR. CWR’s director, Debra Tan runs through some doom and gloom statistics; this time, even she outperforms with grim research observations from our polar regions. Be FOMO and get on top of emission accelerants and accelerated impacts because it IS a big deal – it’s worse than you think – we could see multi-metre SLR sooner than you think.
So how bad is it? What’s a better place to start than with a key survey of over 100 SLR experts just released this year. These experts have each published a minimum of six papers on SLR between 2014 and 2018 so we figured they must be in the know. Here, we were lucky to have interviewed Dr. Nicole Khan, an author of the expert survey. She walks us through how SLR expert consensus differs from IPCC’s SLR estimates, which are widely used.
SLR is not a stand-alone risk but a threat multiplier for typhoon-prone areas as it will exacerbate storm tides. And it’s worse if the city is sinking – a common phenomenon in Asia due to bad planning and over-extraction of groundwater. So we talked to Dr. Chanita Duangyiwa from Bangkok’s Chulalongkorn University – she shares with us the impacts of various scenarios on coastal industrial estates and parts of Bangkok.
The projections alarm – her research on the Chao Praya Delta points to high-end SLR of 1.94m as early as 2050. By 2100 it’s much worse, so it pays to understand Bangkok’s past & future flood risks now.
But Bangkok is lucky as it doesn’t have to also contend with typhoons like Vietnam which is frequently hit. In fact 80% of disasters in Vietnam are typhoon related so how is its population handling this, are they prepared?
The Mekong River Delta is only 1m above mean sea levels which makes it vulnerable to storm surges and typhoons. Experts Dr. Le Tuan Anh (Ho Chi Minh City University of Technology) and Dr. Hiroshi Tagaki (Tokyo Tech) worry that low awareness could escalate future risks. So they turn to Typhoon Linda, the worst storm to have hit southern Vietnam in the past few decades, to shed light on how to cope with such extreme events ahead – check out the key findings of their investigations.
Moving further north to Guangdong, typhoons are more severe. In fact, over a third of all typhoons that landed in China are in Guangdong. The province already suffers around RMB15bn of annual economic losses but damages could escalate say Dr. Xiaohong Chen and Huiwen Bai of Sun Yat Sen University due to increasingly unpredictable storm tides. They run through past paths and economic losses of previous key typhoons and warn of future typhoon paths thus vulnerable areas – so best to find out which direction the winds will be blowing.
Typhoons in the Mekong River Delta are less severe than those pounding the Pearl River Delta so less typhoons = less risks right? Unfortunately, the answer is no. Tokyo Tech’s Dr. Hiroshi Tagaki highlights Myanmar – not a high risk country for typhoons yet Nargis in 2008 caused a huge storm surge that killed ~140,000 people. See why Dr. Tagaki urges us to rethink the way we evaluate typhoon risks – the random nature of typhoons points to using other factors to assess risks such as concentrated economic assets. We couldn’t agree more!
SLR (chronic risk) and storm surges (acute risk) are not going away. If anything, they will rise with time. We are already at 1.1°C and will very likely reach 1.5°C by 2030. Reaching 1.5°C seventy years in advance means we have to start recalibrating valuations for these chronic tail risks today.
But how? Fear not, we have benchmarked the physical threats from SLR, storm surges and subsidence for 20 cities in APAC; and yes, we also benchmarked government adaptation action.
The reports will be out next month; soon you can see which city is protecting their assets and which are not. So, if not already following us, stay afloat by signing up for our newsletters now.
Don’t sink, swim – carbon neutrality pledges definitely help us stay afloat. China & South Korea’s targets are encouraging, as are all the de-carbonisation moves announced by banks (see tapping in); now… if only the U.S. would join the party; all eyes on November.