海角视频

In recognition of World Water Day 2022, the 海角视频 Water Group launched a series of articles to explore pertinent environmental topics.

A subject that is at the forefront of climate change discussions is sea level rise.  Sea levels have fluctuated over geological timescales, but they have been relatively stable over the last 10,000 years, which is when humans started to settle along coastlines. However, shortly after the industrialisation of the mid-19^th century, sea levels have begun to rise.

Rising sea level is a function of two, primary causes; thermal expansion (as water warms, it expands, which increases the volume) and the melting of glaciers and ice sheets. Studies show that thermal expansion has been attributed to 30-40% of the observed sea level rise over the last few decades, with the remainder being caused by melting of glaciers and ice sheets.

For example, between 1990 and 2018, Greenland鈥檚 ice loss has accelerated from 120bn to 330bn metric tons per year. Antarctic ice melt has quadrupled, from 51bn ton per year between 1992-2001 to 200bn tons per year between 2012-2016. Moreover, the impacts of rising sea levels are exacerbated by other local factors such as land subsidence and isostatic rebound.

As Maria Paola Espa explained in her article on groundwater, land subsidence, due to the extraction of groundwater, is having catastrophic effects in many coastal regions, such as Indonesia.

As Jakarta has limited access to clean overground water, the population relies on borewells to extract groundwater. This has resulted in a subsidence of 25cm/year, and as a consequence, over 10 million residents are in danger of flooding. With falling land levels and rising sea levels, it is expected that by 2050, 95% of north Jakarta will be underwater! This has led to Indonesia changing the location of its capital city to Nusantara, with many people having to relocate causing community displacement.

Approximately 200 million people live in areas within 5m above sea level, a number that is expected to rise to over 500 million people by the end of the 21^st century. A large proportion of this population live in Asia, which is more susceptible to the impacts of sea level rise.

Nine of the top 10 most populated cities globally are in Asia, and six of these are situated on the coast. Not only are these cities susceptible to flooding, but there are other consequences of sea level rise such as salt water intrusion, which contaminates freshwater aquifers. If mitigation in these regions is not implemented, mass migration will be inevitable.

I think mass migration is inevitable. As sea levels rise, as climate change happens, as fertile fields become arid, as wars are fought, people are going to move. They always have.

Mohsin Hamid

As engineers, it is critical to understand the different ways in which we are able to mitigate sea level rise. Perhaps the most immediate response is to move to higher ground! However, this is not always feasible.

Alternatively, flood-proof structures provide resilience to sea level rise, such as raising land platforms or designing floating structures. Another way to mitigate sea level rise is implementing hard structures like levees and breakwaters. Furthermore, soft engineering methods like beach re-nourishments and mangrove restoration also mitigate the impact of sea level rise. Not only protect the coastline, but they can also help develop ecosystems.

At 海角视频, we are constantly developing innovative ways to mitigate the impact of rising sea levels. Whether it is a new beach management plan at Folkestone Harbour, or providing setbacks along a stretch of coastline in the Kingdom of Saudi Arabia.

The Water Group assesses the project site, conditions and constraints to identify the most appropriate form of mitigation. Providing resilience, as well as additional benefits such as public spaces and ecosystems, have become increasingly important as we try to tackle the impacts of climate change. In order to provide this necessary resilience, reliable predictions of future sea level rise are critical.

Future sea level rise is uncertain. The extent to which atmospheric temperature will change is not known, and this means that the impact on both ice sheets and the water body itself is uncertain. At 海角视频, we constantly keep up to date with the latest climate data in order to give the most appropriate recommendations to sea level rise allowances.

In April, the issued a statement making it clear that is it 鈥渘ow or never鈥� in terms of implementing measures that will limit global warming to 1.5 degrees Celsius. However, despite stricter policies being implemented and enforced to reduce carbon emissions, sea levels would still continue to rise.

Currently, over 90% of human induced excess heat goes into the ocean, with the remainder going into melting ice and warming the atmosphere. There is a huge amount of heat stored in the oceans, and an inevitable time lag between lower emissions and a slowing down of sea level rise.

Whilst the majority of predictions do not tend to be optimistic, it is important to recognise that we are not helpless. As engineers, we are becoming more adept at developing mitigation methods to help reduce the impacts of sea level rise. Also, the scientific community are becoming more precise and accurate in their predictions of sea level rise.

In tandem, the energy industry is constantly developing more renewable energy sources and steering the global population away from the reliance on fossil fuels. The solution requires cross industry, cross country and geopolitical collaboration, but together, we can help limit the impacts of a rising sea.