On May 9, the daily mean concentration of carbon dioxide in the atmosphere of Mauna Loa, Hawaii, surpassed 400 parts per million for the first time since measurements began in 1958. Elevated concentrations are causing the global climate to warm, land ice to melt, and sea levels to rise. Sea ice is melting too, of course. (Data from the Polar Science Center, and visualization by the NASA Scientific Visualization Studio.)
In the absence of policy cooperation — the likes of which we’ve rarely or never seen in human history, and what must amount to cultural change and the restructuring of national economies across huge segments of the global population — swaths of densely populated cities will one day be covered by ocean water. Any lawyer who thinks about that for a moment will be overcome with the legal implications – I certainly was when practicing in New Orleans after Hurricane Katrina.
Measuring sea level rise (SLR) cannot be an exact science because the number of factors involved and the temporal range under consideration present a matrix of possibilities too complex for perfection. Outcomes are thus given in ranges. From the Intergovernmental Panel on Climate Change (IPCC), AR5:
Risks increase disproportionately as temperature increases between 1-2 Celsius additional warming and become high above 3 Celsius, due to the potential for a large and irreversible sea level rise from ice sheet loss. For sustained warming greater than some threshold, near-complete loss of the Greenland ice sheet would occur over a millennium or more, contributing up to 7 meters of global mean sea level rise.
Due to sea level rise projected throughout the 21st century and beyond, coastal systems and low-lying areas will increasingly experience adverse impacts such as submergence, coastal flooding, and coastal erosion (very high confidence). The population and assets projected to be exposed to coastal risks as well as human pressures on coastal ecosystems will increase significantly in the coming decades due to population growth, economic development, and urbanization (high confidence).
A survey of the field published as Expert Assessment of Sea Level Rise By AD 2100 and AD 2300, Quaternary Science Reviews 84 (2014) 1-6, yielded this:
Large uncertainty surrounds projections of global sea level rise, resulting from uncertainty about future warming and an incomplete understanding of the complex processes and feedback mechanisms that cause sea level to rise. Consequently, existing models produce widely differing predictions of sea level rise even for the same temperature scenario. Here we present results of a broad survey of 90 experts who were amongst the most active scientific publishers on the topic of sea level in recent years. They provided a probabilistic assessment of sea level rise by AD 2100 and AD 2300 under two contrasting temperature scenarios. For the low scenario, which limits warming to <2 Celsius above pre-industrial temperature and has slowly falling temperature after AD 2050, the median likely range provided by the experts is 0.4-0.6 meters by AD 2100 and 0.6-1.0 meters by AD 2300, suggesting a good chance to limit future sea level rise to <1.0 meter if climate mitigation measures are successfully implemented. In contrast, for the high warming scenario (4.5 Celsius by AD 2100 and 8 Celsius in AD 2300) the median likely ranges are 0.7-1.2 meters by AD 2100 and 2.0-3.0 meters by AD 2300, calling into question the future survival of some coastal cities and low-lying island nations.
That last clause bears reprinting:
calling into question the future survival of some coastal cities and low-lying island nations
Now this is only half the story to be told here. The other half is set in law. Inexactitude was no obstacle to petitioners in Massachusetts v. Environmental Protection Agency, 549 U.S. 497 (2007), and inexactitude will be no obstacle to floodwaters. While there are quite a few substantive efforts underway within the domain of climate justice, this next addition to legal thinking on the subject is almost entirely procedural/structural — though there must be some degree of substantive legal effect when there is a change in jurisdiction. Simply put, when swaths of Miami are submerged under sea, further application of any land-based law in those parts will be questionable, and the proper starting point for legal analysis will be admiralty jurisdiction.
Admiralty jurisdiction is constitutionally federal under Article III, Section 2. It generally applies on/in/under navigable waters. A body of substantive federal maritime law has formed over the years, evolving from antiquity to more recently be driven by the national desire to maintain a degree of uniformity in governance about something so common to the federation — our waters. The application of a legal device known as the “reverse Erie doctrine” means state courts must apply federal maritime law if it is on point, though they are free to develop state law that fills any interstices or lacunae. Not only will the reach of admiralty jurisdiction increase as sea level rises, so too will the application of substantive maritime law.
The connection between sea level rise to admiralty jurisdiction came aided by experience in the field. At about the time I was publishing an admiralty piece on salvage operations at shipwreck Titanic, and assisting a U.S. Supreme Court appeal about constitutional sovereign immunity for political subdivisions facing suit in admiralty, I was also making plans to move to New Orleans — it was late 2005 shortly after Hurricane Katrina ravaged the Gulf Coast and compromised levees protecting the city from inundation. I moved to NOLA, began practicing admiralty law at a larger firm, and was met with an epic plaintiffs’ petition for failure of the levees, asserting among other things that construction of the Mississippi River Gulf Outlet (MRGO) — in large part a dredging project — was negligent. My role in these vast consolidated matters became more involved on one aspect — the dredging itself. I vividly recall being in the well-appointed conference room of another firm several floors down from mine at the Energy Centre. Around a large mahogany table in plush leather chairs sat a dozen attorneys with pens in hand, notepads before them, and still glasses of water at the ready. Attention was fixed on a plaintiff giving deposition testimony — a resident of the Lower Ninth. He described what he thought was the sound of the levee breaking, and the way the water began running in under his door. He told us about his fear of imminent death.
This particular cluster of Hurricane Katrina litigation was heard in admiralty jurisdiction, under a recondite federal admiralty procedure of interpleader and concursus used for limiting liabilities to the value of the vessel involved. You’re reading that right — the defendants petitioned to limit their liability for the flooding of New Orleans to the value of their respective dredging vessels.
Climate change, sea level rise, the prospect of stronger storms, future coastal inundation, political/cultural failures, general unpreparedness — they all come together in a vision of metropolitan salvage operations that would be subject to admiralty jurisdiction and governed by maritime law.
This tool from Climate Central lets you investigate various scenarios in over 3000 coastal U.S. cities.
Island nations face 100% submergence – like Tuvalu and the Marshall Islands. Tony De Brum, Foreign Minister for the Marshall Islands, eloquently explains in this September 22, 2014 interview.
What’s at stake is plain:
If we do not keep the temperature under two degrees centigrade, as the United Nations FCCC (Framework Convention on Climate Change) is trying to do, then in 50 years there will be nobody living there.
The following are select data showing the percentage of each category facing submergence should sea levels rise about 1.5 meters.
In New Orleans, a 3 meter rise in sea level means 99.5% of people and homes are under water. A bastion for maritime law and lawyers, NOLA will need the strong character and service for which they are known.