Tuvalu - The Effects of Climate Change, El Niño and La Niña

The Effects of Climate Change, El Niño and La Niña

At its highest, Tuvalu is only 4.6 metres (15 ft) above sea level, and Tuvaluan leaders have been concerned about the effects of rising sea levels for a few years. Whether there are measurable changes in the sea level relative to the islands of Tuvalu is a contentious issue. There were problems associated with the pre-1993 sea level records from Funafuti which resulted in improvements in the recording technology to provide more reliable data for analysis. The degree of uncertainty as to estimates of sea level change relative to the islands of Tuvalu is reflected in the conclusions made in 2002 from the available data. The 2011 report of the Pacific Climate Change Science Program published by the Australian Government, concludes: "The sea-level rise near Tuvalu measured by satellite altimeters since 1993 is about 5 mm per year."

Observable transformations over the last ten to fifteen years show Tuvaluans that there have been changes to the sea levels. These include sea water bubbling up through the porous coral rock to form pools at high tide and the flooding of low-lying areas including the airport during spring tides and king tides.

As low-lying islands lacking a surrounding shallow shelf, the communities of Tuvalu are especially susceptible to changes in sea level and undissipated storms. It is estimated that a sea level rise of 20–40 centimetres (8–16 inches) in the next 100 years could make Tuvalu uninhabitable.

The 2011 report of Pacific Climate Change Science Program of Australia concludes, in relation to Tuvalu, that over the course of the 21st century:

• Surface air temperatures and sea‑surface temperatures are projected to continually increase (very high confidence).
• Annual and seasonal mean rainfalls are projected to increase (high confidence).
• The intensity and frequency of extreme heat days are projected to increase (very high confidence).
• The intensity and frequency of extreme rainfall days are projected to increase (high confidence).
• The incidence of drought is projected to decrease (moderate confidence).
• Tropical cyclone numbers are projected to decline in the south-east Pacific Ocean basin (0–40ºS, 170ºE–130ºW) (moderate confidence).
• Ocean acidification is projected to continue (very high confidence).
• Mean sea-level rise is projected to continue (very high confidence).

The South Pacific Applied Geoscience Commission (SOPAC) suggests that, while Tuvalu is vulnerable to climate change, environmental problems such as population growth and poor coastal management also affect sustainable development. SOPAC ranks the country as extremely vulnerable using the Environmental Vulnerability Index.

While some commentators have called for the relocation of Tuvalu's population to Australia, New Zealand or Kioa in Fiji, in 2006 Maatia Toafa (Prime Minister from 2004-2006) said his government did not regard rising sea levels as such a threat that the entire population would need to be evacuated. In spite of persistent Internet rumours that New Zealand has agreed to accept an annual quota of 75 evacuees, the annual quota of 75 Tuvaluans granted work permits under the Pacific Access Category (announced in 2001) is not related to environmental concerns. Employment opportunities and family reunification has been the primary motivation of Tuvaluans who obtain New Zealand work permits under the Pacific Access Category.

Tuvalu experiences the effects of El Niño and La Niña caused by changes in ocean temperatures in the equatorial and central Pacific. El Niño effects increase the chances of tropical storms and cyclones, while La Niña effects increase the chances of drought. Typically the islands of Tuvalu receive between 200mm to 400mm of rainfall per month. However, in 2011 a weak La Niña effect caused a drought by cooling the surface of the sea around Tuvalu. A state of emergency was declared on 28 September 2011; with rationing of fresh-water on the islands of Funafuti and Nukulaelae. Households on Funafuti and Nukulaelae were restricted to two buckets of fresh water per day (40 litres).

The governments of Australia and New Zealand responded to the 2011 fresh-water crisis by supplying temporary desalination plants, and assisted in the repair of the existing desalination unit that was donated by Japan in 2006. In response to the 2011 drought, Japan funded the purchase of a 100 m³/d desalination plant and two portable 10 m³/d plants as part of its Pacific Environment Community (PEC) program. Aid programs from the European Union and Australia also provided water tanks as part of the longer term solution for the storage of available fresh water. In July 2012 a United Nations Special Rapporteur called on the Tuvalu Government to develop a national water strategy to improve access to safe drinking water and sanitation.

The La Niña event that caused the drought ended in April-May 2012; by August 2012 the El Niño-Southern Oscillation (ENSO) Conditions indicate that the Tropical Pacific Ocean was moving to an El Niño event.