| South-East Asia's Environmental Future: The Search for Sustainability (1993) |
|Part II - Climatic change and variability|
|7. Enso, drought and flooding rain in south-east Asia|
Further work is needed to document the exact influence of ENSO throughout South-East Asia. Exhaustive studies, such as those by Allen (1989) and Allen, Brookfield and Byron ( 1989) for the highlands of Papua New Guinea should be completed for the entire region. Improvements in the accessibility and quality of climate data are needed if this is to be done. Some interesting interactions between ENSO and the background climate can be expected, because of the strong seasonal climatic variations in this region. The effect of ENSO on rainfall at Kota Kinabalu (Sabah), for example, is illustrated in Figure 7.9. Rainfall here usually exhibits twin peaks, as the Intertropical Convergence Zone (ITCZ) passes over the station in June and October. During La Nina episodes, these peaks are exaggerated; while in El Niño episodes, they are almost removed and a new peak rainfall appears in August.
Further work is also needed to assess impacts of climatic anomalies associated with ENSO in the region. Effects on agriculture and human health, in particular, need to be better documented. The implications of the high variability and temporal patterning of ENSO-related climatic anomalies for forest management, soil conservation and wildlife management also have implications for the development of a sustainable environmental future for the region. Finally, ways of using the information provided by ENSO about the region's climatic variations (including the seasonal predictability) to enhance the environment, economy and lifestyle of the region need to be developed.
The South-East Asian region is likely to continue to be affected in much the same ways as it is now, at least for the foreseeable future. As populations increase, greater pressures will be placed on the environment. These can combine with the highly variable climate produced by ENSO to yield further rapid and irreversible changes to the environment. Amplification of climatic variations caused by ENSO in South-East Asia and other areas will make sustainable development more difficult than will be the case in the unaffected areas. Both the knowledge of the way ENSO influences the climate and the predictability provided by the phenomenon need to be improved and utilized in the quest for sustainable development.