Climate Change and Tuvalu

My last entry reviewed some of the threats that small islands face as a result of climate change, however I am aware that some might read this as a worst case scenario and think that no single island will face all these threats. To emphasise to you that this is not the case in this entry I will look specifically at the threats being faced by the island of Tuvalu.

Aerial view of Tuvalu (source).

Tuvalu is a nation located in the southwest Pacific Ocean which consists of nine small islands none of which exceed two metres above sea level. As a nation it has been propelled into the spotlight by the recent news that drought caused by the La Nina weather pattern has led to the declaration of a state of emergency in the country as water provisions arrive by airlift. These drastic measures are required to supply the country with water as Tuvalu is dependent on rainwater and therefore any reductions in the volume of precipitation can, and are, having a devastating impact. The islands complete dependence on rainwater has occurred as the islands freshwater lens (an area of groundwater where less dense freshwater sits atop of saltwater) has been contaminated by the intrusion of saltwater due to sea level rise. A lack of safe water is dangerous not just for consumption purposes but also for sanitation; a study looking at cases of diarrhoea in the pacific islands has found a strong relationship between low water availability and the high rates of diarrhoea (Singh et al, 2001).

In addition to contaminating groundwater salt water intrusion is putting food security at risk through the salinization of soil water. This is having a great impact on pulaka, a swamp taro which provides the islanders with a source of carbohydrate, which, due to its high salt intolerance has been found rotting in the ground (Ralston et al, 2004).

Land loss due to rising sea level is another major issue, it has been projected that if a sea level rise of between 50cm and 95cm occurs then one metre of shoreline could be lost each year. As at its widest Tuvalu reaches just 400m wide such a loss would be greatly significant. While I have been unable to find any papers which quantify the loss of land experienced, there is much anecdotal evidence. Probably the most striking of these is the request made to the government of Australia by the Tuvaluan prime minister to cede a piece of its territory so to enable Tuvalu to be re-established elsewhere (Leckie, 2009). It has also been acknowledged by older inhabitants of the islands that islets that they used to play on as children can no longer be seen above the water.

The impacts of climate change on coral reefs are also greatly important for the Tuvaluan people as they, like many small island communities, rely upon coral reefs, for food through the fisheries they sustain, for tourism and to protect shorelines from the direct impact of waves. However, reef growth rate in Tuvalu is extremely slow at just 2mm per year and thus it is not expected that the reef will be able to tolerate the much more rapid rate of sea level rise expected. This is an extremely serious threat to coral reefs and is made more so by the rising water temperatures and ocean acidification that are likely to accompany the rise in sea level (Ralston et al, 2004).

A Tuvaluan child appeals to participants at the Copenhagen climate summit (source).

By exploring the example of Tuvalu I hope I have shown that the threats outlined in my previous post were not a list of individual impacts, of which one or two may be faced by an island, but are in fact the impacts that can be seen to threaten a single island simultaneously as a result of climate change.