Presentation on theme: "Sea Level Rise and Shifting Maritime Jurisdictional Limits"— Presentation transcript:
1 Sea Level Rise and Shifting Maritime Jurisdictional Limits Clive SchofieldAustralian National Centre for Ocean Resources and Security (ANCORS)
2 Sea Level RiseIPCC’s estimated range of sea level rise: m by the end of the century?Growing consensus that this estimate is overly conservativeGreat uncertainty over the critical questions of how much and how quickly?
4 Migrating Baselines = Shifting Limits Maritime jurisdictional limits measured from baselines:Predominantly normal baselines, low-water line baselinesTraditional interpretation: ambulatory baselines and consequently shifting limitsCoastlines dynamic – low water line susceptible to changeAs normal baselines move, the limits drawn from them also shiftNot a new phenomenonAs sea level rises so the low-water line migrates inlandDramatic horizontal shifts to normal baselines possible from slight changes to sea level vertically
5 Critical basepoints may be unstable or ephemeral insular features Impacts on IslandsSea level rise/shifting baselines will also impact on the classification of insular featuresMost common normal baseline used, Lowest Astronomical Tide (LAT) – a very low low water lineCritical basepoints may be unstable or ephemeral insular featuresVulnerable to sea level rise leading to downgrading of islands to mere rocks or low-tide elevationsImpact on capacity to generate claims to maritime jurisdiction
6 Implications for: Implications Extent and limits of maritime claimsEnforcement issuesDelimitation of maritime boundariesLoss of jurisdiction over vital marine resourcesJurisdictional uncertaintyPotential for conflict
7 Fix normal baselines physically Potential ResponsesFix normal baselines physicallyCan key basepoints be preserved through sea defences, ‘building-up’ and/or reclamation?Long tradition and an option for critical basepoints but unrealistic for long coastlines?Fix normal baselines legallyFix the limits of maritime zones
11 Physical defences unrealistic for long coastlines?
12 Fix Normal Baselines Legally Choice of chart depicting normal baseline left up to the coastal State (LOSC, Article 5)Chart the legal documentCan a coastal State therefore choose a chart that is advantageous to it?What if there is a difference between the low water line shown on the chart and reality?The drafters of the Convention did not anticipate sea level riseBUT: Ambulatory baselines may be fixed with straight baselines on unstable coastsConnection to the low water line still required
13 Fixing Limits and Boundaries Once agreed maritime boundaries remain fixed even though the baselines used to construct them may regressWhat if the territory in question disappears entirely?The outer limits of the continental shelf may also be fixed as “final and binding”Fix (declare) maritime limitsProvides the advantage of certainty and the preservation of existing maritime claimsBUT: Increasing tension between fixed limit and receding or disappearing normal baseline it is measured from