Tsunami Disaster: Opportunity for Change?

Kim Stewart and Steph Long

Just days after the Asian Tsunami Klaus Toepfer, the Executive Executive Director, United Nations Environment Programme stated that the event was a grim reminder of “of the vulnerability of coastal communities to natural disasters including small islands”.

The Asian tsunami disaster has brought home to the world the power of nature to eradicate human endeavours. Thus far over 150,000 lives have been lost, while millions more who survived have been displaced and made homeless. At this important juncture in the tsunami disaster, as reconstructions begins, this is an opportunity to take into account the long-term likelihood sea-level rise and the consequences of climate change for the better livelihood of the future.

The greatest proportion of the world’s surface is water and the vast majority of the world’s people live by the water. In the simplest of terms, we are land based creatures and therefore, changes in sea-level along coastal areas affect our lives. The Asian tsunami demonstrated this on a catastrophic level. Due to the high quality of climate science knowledge we now know that sea-level rise is inevitable in the coming decades and has already been observed. Global sea-level rise will effect all coastal societies; but none more so that small island states and densely populated low-lying coastal areas. The Intergovernmental Panel on Climate Change’s (IPCC’s) Climate Change 2001: The Scientific Basis estimates a sea level rise of 0.09 to 0.88 m is projected from 1990 to 2100. Currently sea level is rising at a rate of about 2.5mm per year (IPCC 2001).

However, many islands and coastal areas are expected to become uninhabitable before the sea level rises, as salt water contamination of fresh water sources on islands, damage to coral reefs through water temperature rise and increased incidence of storms, and erosion will make life increasingly difficult for humans and wildlife alike. Increased king tides, flooding, cyclones and storm surges are already leading to erosion of human structures and land base on Tuvalu, the Marshall Islands and the Maldives. The decline in a resource base for agriculture and fishing will decrease a nations ability to cope, with expectation of abandonment of threatened areas expected to accelerate the rate of resource exploitation, creating a self-defeating spiral that leads to decreased investment and international aid.

Physical impacts of climate change and decrease in investment can spell a fatal combination for island nations. It moves response to environmental impacts out of the realm of simple distribution of costs to become a moral issue of survival and sovereignty.

The Australian aid appeal has shown that the Australian people can increase their private donations in times of crisis, and may be equally prepared to take responsibility where is it due, as highest per capita greenhouse emitters in the world. However, more importantly it is essential that the generousity shown by people across the world is not wasted in reconstruction that doesn’t take into consideration highly probably impacts of increased sea-level rise due to climate change. It is imperative that the international response to the Tsunami appeals are used to reconstruct communities that are protected from sea-level rise as a result of human induced climate change. There are two key ways in which the international efforts to support this:

• Firstly by ensure the most appropriate infrastructure is built away from the immediate coastline, and

• Secondly to conserve the natural systems, such as reefs and mangroves, that protects the coastline from the sea.

In 2001 the IPCC estimated that global sea level rose by 0.1 to 0.2 metres during the 20th century, which has had a significant impact on increase high water level of storm surges and king tides. Additionally, there is increasing scientific interest and research into ‘non-linear’ or rapid climate change events such as the melting of the Greenland ice sheet, which is predicted to result in a global seven metre increase in sea level.

This rise has two effects on low-lying coastal regions: firstly any structures located below the resulting level of the sea will be flooded and, secondly, the rise in sea level may lead to coastal erosion that can further threaten coastal structures. As a rule-of-thumb (or “Bruun rule”) is that a sandy shoreline retreats about 100 metres for every metre rise in sea level or at a ratio of 100:1.

Throughout tsunami reconstruction planning there are two basic precautionary measures that should be adopted: Firstly, the foundations of structures should be located at a height that is the highest sea-level ever recorded in that region, and takes into account the projected rise in mean sea level over the expected life of the structure. Considering the IPCC projections, a 100-year lifetime needs to accommodate up to 88 centimetres of sea-level rise.

Secondly, for foundations on erodible material (e.g. sand) then, in addition to the above recommendation, the structure should be set back from the present extreme high water mark (as indicated by the limit of vegetation or by an erosion scarp) by an appropriate distance which allows for the retreat of the shoreline due to sea-level rise. For a sandy shoreline, this distance would be around 100 times the projected sea-level rise, or about 100 metres.

Enhancing the coastal areas natural protection through embodiment of the precautionary principle and application of low technology community initiatives is the most viable risk reduction strategy for natural disasters. Community leaders and environmentalists’ worldwide are stating that mangroves and coral reefs provide essential protection against tsunamis and storm surges by their ability to buffer the impact of waves; from Thai marine environmentalists, to reef research foundations in India and the Malay Fishermen Welfare Association.

As rebuilding will soon begin in the tsunami stricken regions, the world needs to recognise that the impact of climate change is likely to pose similar problems to the current tsunami crisis, through incremental sea level rise and rapid non-linear events as currently under scientific investigation. In 1997 Tuvalu, Nauru, Kiribati, Niue, and the Cook Island governments issued a joint statement that sea-level rise was a daily issue to them, and the most serious threat to Pacific nations.

In this respect, planning reconstruction to protect the coastal zone and avoid its danger is long overdue and absolutely necessary future risk management. In reconstructing the tsunami disaster region, Australia and other western nations must learn lessons for their own coastal development, and contribute the necessary legislative, technological and financial help to make it possible. The lessons for protecting our invaluable coastline should not be lost to local planning and policy makers: We will all be affected eventually.

Please ask how your donation is being spent and if these suggested consideration to sea-level rise and coastal protection are included.

Kim Stewart and Steph Long are actively involved of Friends of the Earth Australia’s climate justice campaign. For more information see www.foe.org.au/climate.