Glacier melt and rising seas: A call to action for coastal resilience
This year’s theme for World Water Day is ‘Glacier Preservation’, recognising that this delicate balance is under increasing threat.
Glacier Melt and Rising Seas
Our planet’s glaciers store around 69% of the earth’s freshwater and for centuries have played a stabilising role, regulating the flow of water into our oceans. Worryingly, our glaciers are now melting at unprecedented rates due to rising global temperatures. This has far-reaching consequences, particularly in coastal regions, where the resulting increase in sea levels poses a growing flood risk. In this article we consider some of the facts and figures and what can be done to help mitigate the risk.
Sea Level Rise
Global warming, driven by greenhouse gas (GHG) emissions from human activities, is the primary cause of glacial melt. As temperatures rise, glaciers and ice sheets, especially those in Greenland and Antarctica, lose ice at accelerating rates. This contributes to rising sea levels through two key processes:
- Thermal expansion: Warmer oceans expand, increasing water volume; and
- Melting ice sheets and glaciers: Direct meltwater adds to ocean levels.
These processes, in combination with changes to land-water storage, contribute to a rise in sea levels. A breakdown of their contributions, now (2018) and into the future (2050 and 2100), is presented in Figure 1.
Global mean sea level rise has accelerated since the late 1960s, with an average rate of 2.3 mm per year over the period 1971 to 2018, increasing to 3.7 mm per year over the period 2006 to 2018 (IPCC, 2021). Although these are seemingly small numbers, they have the potential to cause devastating consequences, particularly for low-lying coastal areas.
What are the impacts on coastlines?
As sea levels rise, coastal flooding becomes an increasing reality. Higher tides, intensified storm surges and shrinking wetlands leave coastal communities more vulnerable. Even without major storms, elevated tides can cause flooding of low-lying communities.
Coastal processes may be altered, causing waves to reach farther inland. Erosion threatens beaches, cliffs and other coastal landforms, accelerating land loss and putting essential infrastructure, such as roads, ports, and airports, at risk. The disappearance of wetlands, which serve as natural flood defences, further amplifies storm impacts.
Low-lying regions, such as the Maldives and Pacific Islands, face the growing reality of becoming uninhabitable. As coastal floods and land loss force migration, the rise in climate refugees presents significant social, economic and political challenges.
What can we do?
1. Reduce emissions to slow melting
We can slow down the melting of our glaciers by limiting the rise in global temperatures. Those of us in the engineering industry have not just an opportunity, but a duty to drive change. º£½ÇÊÓƵ, like many consultancies, has declared a Climate Emergency and we are working towards our 2030 goal of designing all new build projects to be net zero carbon in operation, with a 50% reduction in embodied carbon intensity from a 2020 baseline.
2. Adapt to a new reality
Coastal cities are investing in resilient infrastructure that can protect them against flooding, such as seawalls, flood barriers and erosion control. Nature based solutions may offer an alternative approach, restoring wetlands, mangroves and coral reefs to help buffer coastal communities against the impacts of rising sea levels. These adaptation measures, along with alternative options, are presented in Figure 2.
3. Future Proof new buildings and infrastructure
Most new developments on the coast now build in an allowance for sea level rise; something that was less common twenty years ago. The process is well regulated along the English coastline, through the National Planning Policy Framework (NPPF) and Environment Agency guidance. Internationally, there is often more flexibility, leaving this important decision up to the judgement of the project promoter and its consultants.
From Folkestone to the Caribbean, New York to Kuwait, º£½ÇÊÓƵ’s engineers are advising governments, communities and developers on how to future proof their projects against sea level rise.
A Survival Strategy
The accelerating pace of glacier melt and its contribution to rising sea levels is one of the most significant challenges of our time. Coastal flooding is an urgent and growing threat that impacts millions of people worldwide. The combined effects of glacier melt, rising temperatures, and sea-level rise necessitate immediate action on both mitigation and adaptation fronts.
The United Nations, as promoters of World Water Day, has described glacier preservation as a survival strategy. We know what our survival tools look like, so let’s work together to use them.
What can you do?
- Reduce your carbon footprint: make sustainable choices in your daily life, such as using public transportation, reducing energy consumption, and supporting renewable energy sources.
- Support climate policies: advocate for policies that aim to reduce greenhouse gas emissions and promote sustainable practices.
- Get involved: participate in local conservation efforts, support organisations working on climate change mitigation, and spread awareness about the importance of glacier preservation.
Together, we can make a difference and protect our planet’s precious resources for future generations. Let’s act now to ensure a sustainable and resilient future.
Learn more about the challenges we face today around water management in the UK in our Sandbox episode ‘Troubled Waters’.
Episode 01: ‘Troubled Waters’
Madeline Witney
