UN adopts sea-level rise declaration: What it means for low-lying areas

Rising seas are raising legal questions over territory and maritime zones. The UN has adopted a declaration addressing these issues as coastlines change

As low-lying cities across the globe, including Mumbai and Kolkata, face rising risks from sea-level rise, the United Nations General Assembly last week adopted a declaration addressing questions that arise as countries lose or see changes to their land territory.

 

The declaration called for stability of maritime zones established under the UN Convention on the Law of the Sea (UNCLOS) and supported the continuity of statehood even when sea-level rise changes a country's territory.

 

The declaration said responses to sea-level rise should “reinforce, not duplicate or undermine” existing legal instruments. It also said international law, including the law of the sea under UNCLOS, should guide these responses.

 

 

A UNGA report, released in May, said nearly 500 million people globally live in low-lying areas where rivers meet the ocean, while coastal cities and municipalities face greater exposure to inundation and flooding.

Can a country remain a country if sea-level rise causes it to lose territory?

The declaration said losing territory to sea-level rise would not necessarily mean that a country ceases to exist.

 

It said that once a State, a sovereign country, has been established, “the disappearance of one of its constituent elements would not necessarily entail the loss of its statehood”. It also supported the continued existence of a State, including its sovereignty, rights, responsibilities and UN membership.

 

The issue is particularly relevant to small island developing States, where rising seas can reduce habitable land and, in extreme cases, lead to the submergence of territory.

 

The UN Secretary-General's report said: “Sea level rise may affect the land territory of coastal and island States significantly, potentially reducing their size or, in extreme cases, leading to complete submergence.”

 

It added that “States have expressed strong support for the continuity of statehood and sovereignty under such circumstances”, linking the preservation of statehood to preventing loss of nationality and statelessness and upholding the right of peoples to self-determination.

Can maritime zones remain stable if a country's coastline changes?

 

The declaration said countries can maintain maritime zones already established under UNCLOS despite physical changes caused by sea-level rise.

 

It stated that, once maritime zones have been established in accordance with UNCLOS, States can maintain them despite physical changes resulting from rising seas. It also said this does not prevent a State from updating those zones and calls for technical support to help States finalise their baselines under UNCLOS.

 

The issue arises because maritime zones are generally measured from coastal baselines.

 

Under UNCLOS, the outer limits of maritime zones, including the territorial sea, exclusive economic zone and continental shelf, are generally measured from baselines drawn at the low-water line, the UN Secretary-General's report said.

 

However, the report said that “issues related to sea level rise are not addressed directly” in UNCLOS and “were not discussed during its negotiation”.

 

The report also said that States and other stakeholders have called for interpretations of UNCLOS that preserve maritime zones and established maritime boundaries despite physical changes to coastlines. The aim, it said, is to ensure “legal stability, certainty and predictability”.

Which Indian cities are at risk?

UN Secretary-General's report identified Mumbai and Kolkata among cities in the low-lying deltas of South Asia. In these cities, along with Dhaka, “the defining impact is human displacement”, with more than 14 million people at immediate risk of losing their homes to permanent inundation, the report said.

 

Mumbai is also India's financial capital and home to major financial institutions, corporate houses and the BSE.

 

The report said the combined effects of sea-level rise and land subsidence are “intensifying flooding risks” and degrading coastal ecosystems. It said the movement of saltwater inland can cause the salinisation of freshwater wells and soils, affecting drinking water security, agricultural productivity, irrigation systems and groundwater-dependent ecosystems.

 

Globally, the UN assessment puts the value of infrastructure exposed to sea-level-rise-related risks at at least $1.8 trillion, according to the separate assessment cited in reporting on the UN report.