Narrow Results

A network of acoustic tide gauges was installed in 1992/93 to monitor long term relative sea level change and contribute to understanding of the tropical Pacific oceanography at shorter time scales. This study analyses the tide gauge data in conjunction with other sources of sea level information, weather and other oceanographic phenomena, over a range of time scales. For simplicity, the study is divided into two Parts. In Part 1, the data from the new network is verified by comparison with data from pre-existing, conventional tide gauges at seven sites where older technology had previously been installed. The accuracy of the acoustic data is found to improve on that of the pre-existing tide gauges, but an error analysis shows that the reduction in random error is not sufficient to reduce the time required to establish a linear trend by more than about one half year. In Part 2 attention is turned to observations of seasonal cycles and planetary waves. Two sites are selected for analysis: Rarotonga and Nuku'alofa. The tide gauge results are compared to sea levels from satellite altimeter and numerical model output. However, the intent is simply to present a preliminary statistical description as a basis for more exhaustive analyses which will be justified as more data comes available.

In 1990, scientists agreed that increasing atmospheric concentrations of greenhouse gases (GHG) will enhance the earth's average temperature in the coming decades. Later, the same group from Intergovernmental Panel on Climate Change (IPCC) 1995 reported that there is now a discernible effect of human activity. There continues to be substantial scientific uncertainty as to the magnitude of this impact on population, economic, environment and other sectors of the ecosystems, at global, regional and national levels. These uncertainties do not mean that GHG emissions can be safely ignored, rather they call for urgent response strategies to be developed.

This paper discusses the outputs from a number of scientific monitoring and research activities currently being implemented in the Pacific region, including the “South Pacific Sea Level and Climate Monitoring Project” in the Forum Island countries. These aim to reduce the uncertainties in order to formulate national response strategies to mitigate or reduce the impacts of climate change and sea level rise in the region.

The response options developed in the Pacific region will be discussed, emphasising especially the development of adaptation option-Integrated Coastal Management (ICM) and Planning.