Seven feet high and rising

By Bryan Walker 15/01/2010


Plan for two metres sea level rise this century.  That’s the message from Rob Young and Orrin Pilkey in a Yale Environment article published today. 

 ’This number is not a prediction. But we believe that seven feet is the most prudent, conservative long-term planning guideline for coastal cities and communities, especially for the siting of major infrastructure; a number of academic studies examining recent ice sheet dynamics have suggested that an increase of seven feet or more is not only possible, but likely. Certainly, no one should be expecting less than a three-foot rise in sea level this century.’

The two professors are authors of a recently published book The Rising Sea which I expect to review on Hot Topic in the near future. But in the meantime a brief report of their article:

’Rising seas will be on the front lines of the battle against changing climate during the next century. Our great concern is that as the infrastructure of major cities in the industrialized world becomes threatened, there will be few resources left to address the dramatic impacts that will be facing the citizens of the developing world.’

The ramifications of major sea level rise are massive.  The disruption of agriculture, the salination of water supplies, storm and flood waters reaching ever further inland, and the creation of millions of climate refugees.  15 million people live at or below three feet elevation in Bangladesh, for example.

Most vulnerable are the deltas of major rivers, including the Mekong, Irrawaddy, Niger, Ganges-Brahmaputra, Nile, and Mississippi:

’Here, land subsidence will combine with global sea level rise to create very high rates of what is known as ‘local, relative sea level rise.’ The rising seas will displace the vast majority of people in these delta regions. Adding insult to injury, in many parts of Asia the rice crop will be decimated by rising sea level – a three-foot sea level rise will eliminate half of the rice production in Vietnam – causing a food crisis coincident with the mass migration of people.’

When it comes to cities Miami is the most threatened in the world.  Other US cities under threat include New York/Newark, New Orleans, Boston, Washington, Philadelphia, Tampa-St Petersburg, and San Francisco. Outside of North America Osaka/Kobe, Tokyo, Rotterdam, Amsterdam, and Nagoya are among the most threatened major cities.

The writers are concerned that the US is not preparing realistically for what lies ahead. ’The continued development of many low-lying coastal areas – including much of the U.S. east coast – is foolhardy and irresponsible.’

They recommend the immediate prohibition of the construction of high-rise buildings and major infrastructure in areas vulnerable to future sea level rise. Buildings placed in future hazardous zones should be small and movable – or disposable. Rebuilding and replacing infrastructure after storm damage should be queried and not supported by government funding if it remains vulnerable. Local governments should not be left with responsibility as they are too influenced by local interests.

How would this sort of realism go down in New Zealand?  Currently local bodies are advised to plan for a 59 cm rise and to consider what an 80 cm rise might mean.  Environment Minister Nick Smith has said the government is working to establish a national environmental standard on planning for sea levels, and hopes it will be in place this year, after public consultation.  However he added that it was likely that councils would still be required to plan for a rise of 59cm, and said: “The Government is not going to consider adjusting its policy every week.”  One’s dignity can prove a precarious perch on which to stand.

If you can bear looking at the human cost of sea level rise, already being experienced in the Sundarbans around the mouth of the Ganges, this photograph exhibition from Peter Caton has just been published in the Guardian.  An earlier Guardian article carries videos of families forced from their villages by flooding and sea inundation. Sea level rise is no distant prospect.