Features | Environment | Politics

Thanks Climate Change: Sea-Level Rise Could End South China Sea Spat

Overlapping claims to islands and reefs in the South China Sea have increased tensions. They may all soon be rendered obsolete.

By Wilson VornDick for

With unproven oil reserves in the range of 28 to 213 billion barrels, massive mineral deposits in the seabed, and millions of tons of potential fisheries; claims over the contentious 1.3-million-square-mile area of the South China Seas (SCS) have become an increasing focal point for the global community.  Currently, seven ASEAN member nations are jockeying against one another for control of this area.  In the past, this has led to overt conflict between China and Vietnam in the 1970s, and more recently to displays of force.  Yet, most of the atolls, banks and islands that make up the SCS are merely a few inches or feet above sea level at high tide.  Often times, they flood over during typhoon season and have to be evacuated.  With environmental predictions of sea-level rise on the order of 3 to 6 feet during the remainder of the 21st century, what would happen if the “dry” areas of the SCS became submerged?

Sea-Level Rise

One of the world’s leading monitors of sea level rise and climate change, the United Nations’ Intergovernmental Panel on Climate Change (IPCC), in 2007 forecasted a 2.0 to 11.5°F increase in global temperatures that will result in 3 to 6 feet of sea level rise by the end of this century.  Yet, one of the biggest misconceptions about sea-level rise is that it is caused directly by glacial melt around the North and South Poles.  On the contrary, as global temperatures increase, the oceans become warmer and thus expand.  Nearly 57% of current sea level rise is actually attributed to this phenomenon; the remainder is from ice-berg, glacial and polar icecap melt. In the last few years, China has become particularly aware of the implications of sea level rise and has been studying its affects, in addition to its regular monitoring of its surrounding waters.

Indeed, Chinese satellites outfitted with advanced altimeter as well as multiple ocean observation stations along the SCS have been monitoring currents, depths, and temperature changes in the contested water for decades.  Many of these observations are beginning to be tied with sea level rise and are filling the media and scientific journals, such as Journal of Tropical Oceanography (热带海洋学报) and Journal of Ocean University of China (中国海洋大学学报), with increasing frequency. The overwhelming conclusion is that the water temperature has been increasing and so have the water levels.  For example, Hong Kong’s government, which has been tracking the mean sea level in Victoria Harbor since 1954, found that sea level has risen 2.8 mm per year.  Hong Kong’s findings also coincide with IPCC sea-level rise predictions.  This may appear to be a relatively minor amount at first.  But taking into account the extreme tides and currents in Hong Kong; the area could experience swells of up to 10 feet.  Regrettably, no other municipality in the area has kept as comprehensive records as Hong Kong.

Enjoying this article? Click here to subscribe for full access. Just $5 a month.

The Claimants and the Limits of UNCLOS

The current SCS claimants are backed by a myriad of border treaties and historical claims that stretch back at least the past millennia.  However; since 1982, the United Nations Convention on Law of the Sea (UNCLOS) has emerged as the most important and recent forum to resolve or counter these claims.  For its part, China signed onto UNCLOS in 1994 and recently defended its claims in the SCS as “indisputable sovereignty” over the area.  As a background, UNCLOS’s boundaries are based solely on land that is “above” sea-level on a 24-hour basis.  A baseline is commonly referred to as coterminous with a low water mark running along the coast.  From these “dry” baseline boundaries, exclusive economic zones (EEZ) are allowed to extend for up to 200 nautical miles (roughly 230 miles).  Features, such as reefs, are generally limited to just territorial sea area (up to 12 nautical miles or roughly 14 miles).  Islands, on the other hand, are generally defined as having fresh water and, as such, are entitled to territorial sea, plus the rights of the EEZ.

But what makes the SCS territorial dispute so difficult is that many of these competing zones and claims overlap one-another precisely because of the separate island claims that speckle the SCS.  While Part XV of the convention does provide legal mechanisms for the arbitration of disputes as they arise, there is nothing laying out exactly how to proceed if these islands were to become partially or permanently flooded-over.  All current developments aside, after decades of contention, the territorial rights of the SCS are no closer to being resolved.  It could be a few more decades before the claims are resolved and by then the area may be completely submerged.  One would think that the treaty’s signatories would have included provisions to address this eventuality.  Yet, they did not.

Drowning Claims

With imminent sea-level rise on the horizon, the low-lying islands of the SCS will likely disappear; thus jeopardizing the framework of this pivotal convention, while scuttling the various claims.  For the Chinese, a tremendous amount of EEZ-based territory would be potentially lost as underscored by their infamous nine-dash line that dips deep into the SCS.  In the background of rising sea level, it would behoove China to consolidate and legitimize its claims soon, either through diplomatic means or force, rather than later.  This would likewise be true for the other claimants.

There are various alternate solutions for China and the other claimants to follow.  One simple and probable solution would be to continue to build-up and structurally reinforce their present claims in the Spratly or Paracel Islands against rising waters.  This scenario would basically keep the status quo.  Yet, this may not be attainable in the short term given the recent events in the SCS and East China Sea.

Alternatively, if the claimants were completely flooded out and each used their territorial baselines, the simplicity of the 200-mile EEZ baselines might make the situation more distinct on the maps and easier for the international community to arbitrate. Though this might not necessarily make the territorial claims that much more palatable or acceptable to any of the parties involved, including China.  Unfortunately the Bangkok Climate Change Conference at the end of August did not offer the claimants an opportunity to address any of these possibilities in regards to UNCLOS.  In the end, as the scenario in the SCS continues to play out, it may augur well for other sea level vulnerable littoral and island nations, as well as anticipating the burgeoning claims in the Arctic.

Wilson VornDick is a Lieutenant Commander in the U.S. Navy where he is assigned to the Pentagon. Previously he worked at the Chinese Maritime Studies Institute at the U.S. Naval War College. This piece reflects the author’s opinions, not the official assessments of the U.S. Navy or any other Government entity.