Sea Level Rise and Low Lying Islands

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Written for Coursera (MOOC) Class ‘Climate Change‘ by the University of Melbourne (Sept 2013).

Because of their low elevation and small size, many small island states are threatened with partial or virtually total inundation by future rises in sea level. In addition, increased intensity or frequency of cyclones could harm many of these islands. The existence or well-being of many small island states is threatened by climate change and sea-level rise over the next century and beyond.’  – IPCC 

In a World Bank Report, ‘Convenient Solutions to an Inconvenient Truth’, published in 2009, it lists the countries with the highest risk of Climate Change threats.

World Bank Top 10 Risks

Looking at Sea Level and the threat to the countries listed, I want to have a closer look at the situation for those with most to lose, who have least political or economic influence.  The Alliance of Small island States includes the low-lying countries of interest.

Established in 1990 to provide a consolidated front in voicing the very real and immediate threats posed by global warming.  It was the first body to submit a draft text in the Kyoto negotiations in 1994.

AOSIS Members

The 2007 Fourth Assessment Report (AR4) projected century-end sea levels using the Special Report on Emissions Scenarios, see the graph below.  Average sea levels are predicted to rise between 0.21 and 0.45 metres by 2100.  Also note that subsequent independent studies have found the IPCC estimates to be conservative.

CHART_IPCC AR4 Sea Level Forecast

Rises in sea level has implications for coastal habitats and economies, specifically in relation to freshwater contamination and loss of land (including supported infrastructure).

TABLE_Kiribati

Gaining independence from the UK in 1979, it remains part of the Commonwealth and is a parliamentary republic.  It comprises of 32 atolls and one coral island.  It has strong relations with Australia, Japan and New Zealand.  Approximately 90% of the population live on the Gilbert Islands, with 33% occupying an area of just 16 km2.  It is one of the most impoverished nations on earth, with little hope of retaining its territory.

It already suffers from overcrowding, with 4,700 inhabitants resettled in 1988, and in 2008 the Kiribati government approached Australia and New Zealand to accept Kiribati citizens as refugees, in preparation for sea inundation.

PHOTO_Kiribati

The president of the Refugee Council of Australia has advised the Australian government that it should prepare to create a new migration category for those fleeing the effects of climate change.[Guardian 16 April 2013, http://www.theguardian.com/environment/2013/apr/16/australia-climate-change-refugee-status ]

Risk Factors & Recent Impacts

Rising sea level is expected to continue in Kiribati, as with elsewhere. By conservative estimates, shown in the table below, by 2030 (under a probable high emission scenario) this rise is projected to be in the range of 5 – 14 cm.  Sea-level rise combined with natural annual changes will increase the impact of storm surges and coastal flooding.

A 50-centimetre rise, which is now considered a conservative projection for this century unless emissions are curbed, threatens the very existence of this small nation.

TABLE_Kiribati_2

  • ‘Kiribati is pretty much all coastal. The people of Kiribati are witness to unprecedented coastal erosion, on both beaches and inland.’
  • ‘Many people are now being displaced from the traditional house plots they have occupied for a century or more.  Many more people are losing their food  sources: coconut trees, papaya trees and other varieties of vegetation.’
  • Freshwater sources are becoming more contaminated by sea water.
  • The majority Kiribati’s islands are so narrow that there really is no place to go. Kiribati has more than 100,000 citizens and its main island, Tarawa, suffers from severe overcrowding.
  • ‘The World Bank recently predicted the capital island of Tarawa, where nearly half the country’s population resides, will be 25 to 54 per cent inundated by water in the south and 55 to 80 percent in the north by 2050 unless significant adaptation is undertaken.’
  • ‘The village of Tebunginako in Abaiang Island has already had to relocate due to the effects of severe coastal erosion and saltwater intrusion.’

Kiribati Official Site and Kiribati Video Link ]

TABLE_Maldives

The Maldives is an Island nation (1,190 islands in 20 atolls) in the Indian Ocean.  Largely, the Maldives have been an independent nation throughout its history, with short periods of intervention by Portugal, Netherlands and UK from which it became independent in 1965, forming a constitutional republic.

Already vulnerable to flooding due to storm surges and earthquake, rising sea levels associated with global warming are making human habitation here more precarious.  This part of South Asia is close to the equator, where sea level rise is greater than in polar ocean, and the Maldives confronting the biggest increases of between 0.100 – 0.115 metres, according to a World Bank scientific report on 19 June 2013.

[ http://www.worldbank.org/en/news/press-release/2013/06/19/concerted-efforts-needed-to-support-maldives-adapt-to-climate-change-world-bank-report-findings-indicate ]

Expected pertubations in the monsoon system combined with elevated peak temperatures put water and food resources at severe risk.  An extremely wet monsoon, currently has a chance of occurring once in 100 years, is estimated to occur every 10 years by 2100.

PHOTO_Maldives

Former President Mohamed Nasheed holding the world’s first underwater council of ministers in 2009.  The 30-minute cabinet meeting held six metres below sea-level was intended to show what the future could hold for the Maldives.

Risk Factors & Recent Impacts

  • 199 islands are inhabited with a population of slightly over 300,000 people. The highest point of land is 2 metres.
  • The reefs host over 1,900 species of fish, 187 coral species, and 350 crustaceans.
  • Rising sea temperatures threaten coral reefs and cause bleaching and death.  Worst damage is in the areas that are compromised by pollutants, and damaged by physical agitation.
  • Vulnerability to Climate Change threats is exacerbated by damage to coral reefs which diminishes their protective function, a negative cycle of impact.
  • With the melting of polar ice caps, the Maldives is also exposed to the risks of sea-level rise. Future sea level is projected to rise within the range of 10 to 100 centimeters by the year 2100, which means the entire country could be submerged in the worst-case scenario.

[ Maldives Video Link ]

TABLE_Marshall Islands

The Marshall Islands is an Island nation forming part of Micronesia in the Pacific Ocean, with 34 low-lying coral atolls and 1,156 individual islands.  Being variously conquered, occupied and governed by Spain, Germany, Japan and USA, the nation gained independence in 1979, forming a democratic republic.

Post world war two, the USA tested 67 nuclear weapons in the Marshall Islands, prompting the Atomic Energy Commission to describe Islands as “the most contaminated place in the world”.   According to ‘Atomic Audit: The Costs and Consequences of U.S. Nuclear Weapons Since 1940’,

$759 million was paid to the Marshallese Islanders in compensation for their exposure to U.S. nuclear testing, and in 1952 with the test of the first U.S. hydrogen bomb, the island of Elugelab in the Enewetak atoll was destroyed.

Party to the ‘Compact of Free Association’ with the United States, gives the USA sole responsibility for defense of the Islands.  It also permits Islanders to live and work in the United States.

PHOTO_Marshall Islands

‘Along the coastline of Majuro, Marshall Islands, old cars and trash are being piled up in an attempt to make seawalls and stop the rising water levels. In most places in Majuro there is no more than 50 – 100 meters in width between the Pacific and the Lagoon.’  – Greenpeace.

Risk Factors & Recent Impacts 

  • 2008:  Extreme waves and high tides caused widespread flooding in the capital city of Majuro and other urban centres. (1 metre above sea level), prompting the government declared a state of emergency.
  • 2013:  Heavy waves breached the city walls of Majuro, while drought afflicted northern atolls of the Marshall Islands.
  • Drought affected 6,000 Islanders, surviving on less than one litre of water per day.
  • Compounded by crops failures and food shortages, the impact on health was significant with the spread of drought-related diseases such as diarrhoea, pink eye and influenza.

[ Marshall Islands Video Link ]

TABLE_Tuvalu

Tuvalu is an Island nation in the Pacific Ocean (3 reef islands and 6 atolls). Initially colonized by Polynesians, the Islands (as part of the Ellice Island group) became a British protectorate in 1892.  Tuvalu became independent in 1974, forming a parliamentary democracy, but remains part of the Commonwealth.

With a very low average elevation, Tuvalu is under threat from sea level rise.  On top of this, these Islands (together with other islands in the region) are subject to annual king tide events which occur at the end of the summer.  These raise the sea level higher than a normal high tide.

King tide events cause flooding over low lying areas.  Even worse flooding is experienced during ‘La Niña’ years when local storms and high waves are particularly prevalent. Estimates of future, sea level rise, which may threaten to submerge the nation entirely, are of the order 0.20 –0.40 metres by 2100.

In this probable scenario, Tuvalu will become uninhabitable.

PHOTO_Tuvalu

Risk Factors & Recent Impacts

  • A typical high tide reaches about 2.5 metres,  a King Tide can be more than 3 metres.
  • A small rise (0.5 metres) will see parts of the islands disappear.
  • Islands are founded on coral which is porous and so saving these islands would be very expensive.
  • With a population of just 11,000 people, will the outside agencies think it is economically feasible?

[ Tuvalu & Kiribati Video Link ]

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