Coastal adaptation measures must consider both sea level rise and extreme sea levels

A scientist specialising in coastal risks and climate change at the University of Southampton, UK, has reported that, while our understanding of sea level rise is growing, further information is needed about extreme sea levels—effects due to storm surges, high tides, and waves.

Our understanding of the impact of sea level rise on flood risk is growing. In fact, recent results are quite shocking. For the US coast, Buchanan et al (2017) concluded that events that currently have a one per cent chance of occurrence in any given year (so-called 100 year events) may occur 25 times as often by 2050 under a moderate scenario of climate change, and 40 times as often under a high-end scenario. They also pointed at different impacts of sea level rise on the occurrence of relative frequent (moderate) and rare (extreme) flood events: On the east coast, cities like Charleston or New York will experience a strong increase in the number of moderate events, while a city like Seattle on the west coast will experience a more rapid increase in the number of rare extreme events.

Climate Change Post summarised this study in their article ‘Current once-in-a-hundred-years flood levels along US coastline may occur every few years by 2050’. Similar results were shown in a study by Vitousek et al (2017), summarised in Climate Change Post’s article ‘Just a few cm of sea level rise may double the frequency of coastal flooding’.

Sea level rise, however, is a gradual process that can be anticipated. Extreme sea levels due to storm surges, high tides, and waves, on the other hand, occur randomly and accurate forecasts become only available a few days or hours before the impacts occur. Recent events like Hurricanes Harvey and Irma have revealed how vulnerable and ill-prepared many coastal communities are for such extreme events. Therefore, adequate adaptation has to take into account sea level rise and extreme sea levels as well as the uncertainties inherent to both of them.

Little is known about future extreme sea levels at continental and global scales. In the IPCC assessments, for instance, a lot of information is presented on sea level rise but the information on extreme sea levels is limited. Uncertainties in these extremes are at least as important as uncertainties in projections of sea level rise. Hence, both these contributions to flood risk need to be integrated to fully assess impacts and adaptation needs.

Future changes in storm surges may add to sea level rise or damp the effects of sea level rise. According to a study by Vousdoukas et al (2016) projected storm surge changes strongly vary along Europe’s coastline: An increase in Northern Europe, no change or a slight decrease in the South (summarised in the article ‘Storm surge levels increase along Northern Europe’s coastline’).

Thus, recent studies point at strong impacts of both sea level rise and storm surge on flood frequency, that strongly vary along the US or Europe’s coastline, and the combined effect of which is highly complicated. Clearly, these combined impacts need to be accounted for in coastal management and adaptation plans.

The article first appeared on Climate Change Post and is a digest of a scientific paper by Wahl, 2017. Environmental Research Letters 12.

 
Articles you may be interested in
In The News
In the face of complex challenges, Europe stronger together, says EU President...

European Commission President Ursula von der Leyen outlined her...

In the face of complex challenges, Europe stronger together, says EU President von der Leyen
In The News
New IPCC report reveals urgent need for climate innovation

The IPCC’s Sixth Assessment Report has launched. The report...

New IPCC report reveals urgent need for climate innovation
In The News
Moving beyond ‘brown coal’ in Europe’s rural regions

Together with Partners, EIT Climate-KIC is leading a process...

Moving beyond ‘brown coal’ in Europe’s rural regions
In The News
EU’s “Fit for 55” to spur policy innovation for climate action

The European Commission has released its “Fit for 55”...

EU’s “Fit for 55” to spur policy innovation for climate action
In The News
Munich Re and ERGO invest in EIT Climate-KIC carbon removal programme

Major German corporate group sets the ambition to accelerate...

Munich Re and ERGO invest in EIT Climate-KIC carbon removal programme
In The News
23 pilot projects selected by EIT to unlock higher education’s innovation po...

The European Institute of Innovation and Technology (EIT) has...

23 pilot projects selected by EIT to unlock higher education’s innovation potential in Europe
In The News
Investing in start-ups scales the offering of climate adaptation solutions in ...

A partnership between EIT Climate-KIC and CDC Group, the...

Investing in start-ups scales the offering of climate adaptation solutions in African and South Asian countries
In The News
Irish Aid extends support for innovation and development from the ground up

The Government of Ireland’s development assistance programme, Irish Aid,...

Irish Aid extends support for innovation and development from the ground up
In The News
EIT Climate-KIC showcases climate innovation at R&I Days

EIT Climate-KIC participated in the European Commission’s Research and...

EIT Climate-KIC showcases climate innovation at R&I Days
In The News
Branch Magazine wins Ars Electronica Award for Digital Humanity

Branch Magazine, a collaboration between EIT Climate-KIC, Mozilla Foundation...

Branch Magazine wins Ars Electronica Award for Digital Humanity
In The News
Cross-KIC project to boost circular economy in Western Balkans

The circular economy concept is of crucial importance to...

Cross-KIC project to boost circular economy in Western Balkans
In The News
Exploring new horizons with Pioneers into Practice

Enrolment is now open for placement hosts and participants...

Exploring new horizons with Pioneers into Practice
In The News
Circular bioeconomy start-up receives €2 million from European Innovation Co...

EIT Climate-KIC supported Lixea (formerly Chrysalix Technologies) has received...

Circular bioeconomy start-up receives €2 million from European Innovation Council Fund
In The News
Embracing a new approach to climate change in Moldova

Moldova is one of Europe’s most modest contributors to...

Embracing a new approach to climate change in Moldova
In The News
Krakow: transforming the city towards climate neutrality

Poland’s former capital and one of its oldest cities,...

Krakow: transforming the city towards climate neutrality
In The News
Is Europe doing enough to tackle climate change?

On 23 April, EIT Climate-KIC CEO Kirsten Dunlop spoke...

Is Europe doing enough to tackle climate change?
In The News
EU Commission publishes sustainable finance taxonomy

The European Commission has published its EU-wide classification system for...

EU Commission publishes sustainable finance taxonomy
In The News
New European Bauhaus: what kind of future do you want to live in?

On 22 and 23 April, the first conference dedicated...

New European Bauhaus: what kind of future do you want to live in?
In The News
Estonian innovation to help stabilise grid as renewables increase

EIT Climate-KIC supported Estonian start-up Sympower has raised €5.2...

Estonian innovation to help stabilise grid as renewables increase
In The News
Five EIT Climate-KIC community members in Forbes 30 under 30 list

Twelve entrepreneurs from across the EIT community have been...

Five EIT Climate-KIC community members in Forbes 30 under 30 list
In The News
These eleven organisations are building a greener Europe

Google, in partnership with EIT Climate-KIC, launched the €10...

These eleven organisations are building a greener Europe
In The News
New equity crowdfunding programme unearths cleantech start-ups

Found by us, funded by you, a new start-up...

New equity crowdfunding programme unearths cleantech start-ups
In The News
From start-up to 100-person industry player in 18 months: air up is launching ...

It’s a beverage revolution: Healthy hydration while fooling your...

From start-up to 100-person industry player in 18 months: air up is launching in new markets
In The News
#TurnItAround: an event for all climate solutions seekers, suppliers and enabl...

As part of the fifth SDG Global festival of...

#TurnItAround: an event for all climate solutions seekers, suppliers and enablers
In The News
New EIT initiative to boost innovation in higher education

The European Institute of Innovation and Technology (EIT) is...

New EIT initiative to boost innovation in higher education
In The News
Just transition within reach for Polish coal city Rybnik

“We are preparing plans for the next decade. Mentality is...

Just transition within reach for Polish coal city Rybnik
In The News
Inclusive guide helps communities build urban resilience

The new Urban Action Kit, launched by the International...

Inclusive guide helps communities build urban resilience
In The News
Climate app among DigiEduHack 2020 global finalists

The DigiEduHack, supported by EIT Climate-KIC as well as...

Climate app among DigiEduHack 2020 global finalists
In The News
GreeMko receives Climate Reality Project Award in Spain 

GreeMko (for Green Management Technology), a Spanish start-up that...

GreeMko receives Climate Reality Project Award in Spain 
In The News
What’s the future of trade in a climate crisis?

EIT Climate-KIC Chief Executive Officer Kirsten Dunlop addressed the...

What’s the future of trade in a climate crisis?