The UN Secretary-General António Guterres visited the Pacific countries of Tonga and Samoa. Sea level rise was one of the main issues he discussed with the communities he met.
On September 25, world leaders and experts will gather at the UN to discuss how best to address this threat.
Here’s what you need to know about sea level rise:
High water mark
It is estimated that sea levels have risen by about 20-23 centimeters since 1880.
By 2023, the global average sea level will reached a record high the UN World Meteorological Organization (WMO) confirmed, according to satellite data tracked since 1993.
Worryingly, the rate of rise over the past decade is more than twice as high as the sea level rise in the first decade of satellite measurement, from 1993 to 2002.
What causes sea level rise?
Rising sea levels are a result of ocean warming and melting glaciers and ice caps, phenomena that are a direct consequence of Climate change.
Even if global warming is limited to 1.5°C above pre-industrial levels, which is the goal that countries around the world have set as part of the Paris Agreement From 2015 onwards, the Earth’s sea level will rise significantly.
It is important to note that ocean circulation patterns, such as the Gulf Stream, can lead to regional differences in sea level rise.
© Unsplash/Omar Eagle
Rising sea levels are threatening the tourism industry in areas like St. Lucia in the Caribbean.
What are the consequences?
Rising sea levels have far-reaching consequences, not only for the physical environment, but also for the economic, social and cultural fabric of vulnerable countries around the world.
Saltwater flooding can damage coastal habitats, including coral reefs and fish stocks, agricultural land and infrastructure, including homes, and can impact the ability of coastal communities to support their livelihoods.
Flooding can contaminate drinking water supplies, promote waterborne diseases that threaten human health, and cause stress and psychological problems.
At the same time, tourism revenues, a key economic driver especially in many small island developing states, could suffer from damage to beaches, resorts and other tourist attractions such as coral reefs.
The combination of so many factors can force people to leave their homes, move to higher ground where possible, or ultimately migrate, disrupting economies, livelihoods and communities.
Perhaps unsurprisingly, UN Secretary-General Antonio Guterres has described the phenomenon as a “threat multiplier”.
What is the connection between rising sea levels and climate change?
Simply put, sea level rise is a symptom of climate change.
As global temperatures rise due to climate change, the oceans absorb much of this excess heat. Warmer water expands in volume, a process known as thermal expansion, which is a major contributor to sea level rise.
Moreover, rising sea levels create a catastrophic, circular feedback loop.
For example, mangrove forests, which protect coastal habitats and store harmful carbon gases that contribute to climate change, can quickly become overwhelmed and lose their protective qualities. Fewer mangroves means more harmful gases in the environment, which drives climate change, and with higher temperatures, sea levels will rise even further.
UN News/Daniel Dickinson
Rising sea levels pose a threat to global cities like New York.
Which countries are hardest hit?
It is estimated that about 900 million people, one in ten people on Earth, live near the sea.
People living in coastal areas of densely populated countries such as Bangladesh, China, India, the Netherlands and Pakistan are at risk and could face catastrophic flooding. Major cities on every continent are also at risk, including Bangkok, Buenos Aires, Lagos, London, Mumbai, New York and Shanghai.
Small islands with low-lying land areas are likely to be most at risk. Sea level rise and other climate impacts are already forcing people to relocate in Pacific countries such as Fiji, Vanuatu and the Solomon Islands.
© UNICEF/Vlad Sokhin
Women and girls collect water after floods in Pakistan’s southern Sindh province.
What can be done to combat sea level rise?
The most consistent measure that can be taken is to slow global warming by reducing greenhouse gas emissionsthe main cause of climate change.
Meanwhile, mitigating and adapting to higher sea levels has become more important.
There are a wide range of solutions available, which of course come at a cost, including: building infrastructure, such as sea walls and storm surge barriers, to protect against flooding and erosion; improving drainage systems and building flood-resistant buildings; restoring natural barriers, such as mangrove forests; and protecting wetlands and coral reefs to absorb wave energy and reduce the impact of storm surges.
Many countries are also stepping up their disaster risk reduction plans, as well as UN-supported early warning systems to address incidents related to sea level.
In some cases, communities can also be relocated from vulnerable coastal areas as part of adaptation measures. This approach is known as ‘managed retreat’.
UNFCCC/Kiara Worth
Civil society groups attending UN climate talks in Dubai in 2023 are demanding reparations for losses and damages caused by climate change.
How the UN helps
To combat sea level rise, a comprehensive and internationally coordinated approach is needed. The United Nations is uniquely placed to take the lead in this.
The United Nations Framework Convention on Climate Change (UN Climate Convention) facilitated the Paris Agreement to limit global warming, which is essential to reduce future sea level rise.
The UN also offers support cot death and works with the global community to provide financial support, particularly through the Loss and Damage Fund to the most vulnerable countries and to help them adapt to the impacts of climate change.
Learn more about how the UN is helping to address the challenge of rising sea levels here.
