Ambitious climate policies are needed to avoid fast sea level rise

In a new study exploring five scenarios of socio-economic development, climate scientists say ambitious mitigation policies are required to avoid fast sea level rise.

Drivers of sea level rise

Drivers that contribute to sea level rise are thermal expansion of ocean water, melting glaciers, mass loss of the Greenland and Antarctic ice sheets, and changes in water volumes stored on land. Recently, it was shown that global sea level rise may strongly accelerate from hydro fracturing and ice cliff instability of the Antarctic ice sheet, causing significantly more sea level rise by the end of this century than presented in the IPCC’s latest assessment report. Studies that have included these new insights project sea level rise at the end of this century up to one meter higher than the IPCC estimates.

Scenarios of socio-economic development and of global warming

How fast global sea level will rise depends on the size of the processes that contribute to sea level rise. These processes in turn depend on the combination of socio-economic developments around the globe and the impact of greenhouses gases on global warming. Socio-economic developments are described in scenarios, storylines that include elements like population and economic growth, and an ambition to mitigate climate change and adapt to the consequences. Different storylines reflect different impacts on the environment. The impact of greenhouse gases on global warming is described in so-called Radiative Forcing Targets: The energy intensity that warms the atmosphere, expressed in W/m2. A high-end scenario of global warming agrees with a lot of Watts per square metre. A low-end scenario agrees with far less Watts per square metre, and hence with a strong effort to mitigate the impact of greenhouse gases on global warming. High and low-end scenarios of global warming are 6.0 W/m2 and 2.6 W/m2, respectively. Five scenarios of socio-economic development, the so-called Shared Socioeconomic Pathways (SSPs), have been designed to comprehensively capture varying levels of socioeconomic challenges to mitigation and adaptation:

  • SSP1, a sustainable pathway: Low challenges to mitigation and adaptation
  • SSP2, a ‘middle of the road’ trajectory: Medium challenges to mitigation and adaptation
  • SSP3, a future world of regional rivalry: High challenges to both mitigation and adaptation
  • SSP4, a future marked by inequality: Low challenges to mitigation and high challenges to adaptation
  • SSP5, on-going fossil-fuel development and high energy demand: High challenges to mitigation and low challenges to adaptation

These Shared Socioeconomic Pathways and Radiative Forcing Targets can be combined to estimate future sea level rise. This has been done in a recent study, in which also the latest findings on hydro fracturing and ice cliff instability of the Antarctic ice sheet were included.

Sea level rise without mitigation

If we would not take measures to mitigate global warming, the aforementioned socio-economic scenarios would lead to sea level rise in 2100 (relative to 1986-2005) that varies from 89 cm for the SSP1 scenario up to 132 cm for the SSP5 scenario. These are median values: The likely ranges (including 66 per cent of the model results) are 57-130 cm for SSP1, and 95-189 cm for SSP5. Projections for the other scenarios are in between these values.

Sea level rise with mitigation

The scenarios of global warming (radiative forcing targets) reflect different levels of success to mitigate climate change. It appears that the level of mitigation that is being reached dominates the 2100 sea level response. For the low-end scenario of global warming, and thus the highest mitigation target that is being reached (2.6 W/m2), projected median sea level rise is 52 cm (likely range 34-75 cm). For the high-end scenario of global warming, and least successful mitigation (6.0 W/m2), projected median sea level rise is 91 cm (likely range 61-132 cm). Thus, according to this study, sea level rise in 2100 could be limited to around 50 cm (median value) if the most ambitious climate mitigation measures would be implemented in time.

Ambitious climate policies are needed

The 132 cm sea level rise in the SSP5 scenario without mitigation is a few decimetres lower than recent results on comparable scenarios. However, this study also shows that sea level could rise up to 2 m without mitigation. This highlights that ambitious climate policies are needed to avoid the most severe impacts from rising sea levels around the globe. As such, these higher estimates point to a growing risk of potentially catastrophic sea level rise by the end of the 21st century under unchecked climate change. The study also shows, however, that strong mitigation efforts could prevent the onset of the rapid dynamics that cause the additional sea level contribution from the Antarctic ice sheets. Still, even when mitigation policy proofs highly successful, sea level rise will continue well beyond the 21st century.

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

 
Location
Articles you may be interested in
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?
In The News
Wanted: Green business ideas to fix climate change

Starting today, the seventh edition of the global green...

Wanted: Green business ideas to fix climate change
In The News
Why sustainable water management needs a systemic solution

Ensuring that fresh water is available, in a sustainable...

Why sustainable water management needs a systemic solution
In The News
Integrating nature with technology to strengthen climate adaptation

The European Commission released the new EU Climate Adaptation...

Integrating nature with technology to strengthen climate adaptation
In The News
EIT Climate-KIC is a key player in helping Europe adapt to climate change

EIT Climate-KIC welcomes the new EU strategy on adaptation...

EIT Climate-KIC is a key player in helping Europe adapt to climate change
In The News
Edinburgh: building climate resilient infrastructure and communities

A labyrinth of cobblestone streets, dimly lit and presided...

Edinburgh: building climate resilient infrastructure and communities
In The News
Residents of Kessel-Lo, Belgium, are invited to shape the future of their neig...

EIT Climate-KIC is working with the city of Leuven...

Residents of Kessel-Lo, Belgium, are invited to shape the future of their neighbourhood
In The News
Improved urban parks increase communities’ climate resilience

Start Park, a project led by citizens from Florence,...

Improved urban parks increase communities’ climate resilience
In The News
New accelerator programme geared towards systemic change secures key partners

Following its Open Call, the New Accelerator programme has...

New accelerator programme geared towards systemic change secures key partners
In The News
New videogame builds climate awareness among players

Change Game, a videogame financed by EIT Climate-KIC and...

New videogame builds climate awareness among players
In The News
Organic and homemade food brought to the dining rooms of large corporations

Carlota Mateos and Juan Vila, co-founders of PlenEat have...

Organic and homemade food brought to the dining rooms of large corporations
In The News
Climeworks added to Microsoft’s climate portfolio

EIT Climate-KIC supported Climeworks, a carbon capture technology, is...

Climeworks added to Microsoft’s climate portfolio
In The News
Circular Slovenia named in 100 Climate Policy Breakthroughs

The peer-to-peer learning platform for governments, Apolitical, included EIT...

Circular Slovenia named in 100 Climate Policy Breakthroughs
In The News
New tool uses satellite imagery to accelerate sustainable agriculture

Supported by EIT Climate-KIC and developed by its partner...

New tool uses satellite imagery to accelerate sustainable agriculture