The El Niño Southern Oscillation (ENSO) is one of Earth’s most important climatic phenomena. ENSO, which refers to interactions between the ocean and atmosphere in the Equatorial Pacific Ocean, influences global temperatures and precipitation, and can therefore significantly impact human societies and ecosystems. El Niño and La Niña are the opposite extremes of the ENSO cycle conditions; La Niña is known as the cold phase and El Niño as the warm phase of the ENSO. Most typically, El Niño conditions occur every 2-7 years when sea surface temperatures in the Equatorial Pacific Ocean become warmer and the easterly trade winds blow weaker than normal. El Niño events, which can last a year or more, have a variety of climatological impacts across parts of Africa, North and South America, Australia, Asia, and the Pacific, the most typical of which are increased temperatures, reduced precipitation leading to drought, and changes to tropical cyclone areas of formation and tracking. These changes have historically had large-scale social and economic impacts on millions of people across the affected regions.
The 2015-2016 El Niño event was one of the strongest and most significant on record. Pacific Ocean sea surface temperatures were higher than the temperature for all previously recorded events, in part due to the unusually warm conditions recorded throughout the previous year when an El Niño event was anticipated but did not form. Furthermore, both the Central and Eastern Pacific regions experienced extreme warming, when typically only one of the two regions experiences warming, creating an extreme ‘mixed-type’ event. The 2015–2016 El Niño event resulted in unusually warm conditions for many of the tropical and sub-tropical countries, and the global average surface air temperature for 2015 and 2016 marked two of the warmest years on record. Large parts of Asia and the Pacific experienced hot spring and summer seasons, as well as many extreme weather events such as drought, flood, and tropical cyclone. It is possible that global climate change combined with the ENSO phenomenon drove these extreme conditions in Asia and the Pacific- arguably the most at-risk region in the world with regard to disasters, climate change, and El Niño impacts.
The 2015–2016 El Niño affected the lives and livelihoods of more than 60 million people across the globe with the full socio-economic cost still being estimated. Many of the socio-economic impacts of El Niño events relate to food security by affecting agriculture inputs (e.g. water – availability and quality), agricultural productivity, food availability, food prices, food quality, and nutritional value. As with all of the major El Niño events over the past several decades, the 2015-16 event undoubtedly took its heaviest toll on these aspects. In Asia and the Pacific, the event has destroyed crops and killed livestock, in some cases dried up water-sources and in others, caused massive flooding, driven up malnutrition rates, increased disease outbreaks, and driven migration. Long after the weakening of the event was declared, the long-term impacts have yet to be fully assessed and its effects will last well into 2017. What we do know with some certainty is that impacts of El Niño-related disasters are typically felt most by the rural poor in middle- and lower-income countries in Southeast Asia, South Asia, and the Pacific.
Measures aimed at protecting lives and minimizing impacts include the generation of risk information and the provision of early warning services. A range of sophisticated models are available for seasonal climate prediction. Generally, there are two different approaches for generating operational seasonal forecasts: (1) statistical (empirical) prediction and (2) dynamical prediction. The statistical prediction utilizes previously observed relationships between El Niño and the local climate, as well as past experiences during El Niño and La Niña years. While statistical prediction has been successful in some regions and years, dynamical prediction, which utilizes global climate models, has improved in many ways and demonstrates better promise for future operational use. Some techniques, e.g., multi-model ensemble (MME), have also been developed to improve the prediction skills of dynamical seasonal prediction. Although there are still issues like the spring predictability barrier (a forecast issued before boreal spring is generally less reliable than the one issued after spring season), current seasonal predictions utilizing the dynamical MME provide reliable seasonal forecasts for El Niño several months ahead of the event’s actualization.
Solutions for integrating the available science and information on socio-economic vulnerabilities into Information Technology (IT) enabled platforms that enable easy access and sharing of information and coordinating response include the creation of an El Niño Regional Dashboard and the Specialized Expert System for Agro-Meteorological Early Warning (SESAME) developed by RIMES. The Dashboard could be hosted by the Pulse Lab Jakarta as an expansion of existing tools and services, such as the Vulnerability Analysis Monitoring Platform for the Impact of Regional Events (VAMPIRE). This tool can be used to understand the evolving nature of slow, onset phenomena like El Niño in near real-time to better target assistance from governments and international organizations to vulnerable populations.
The Dashboard could be extended to provide a range of other services that could benefit El Niño affected countries. SESAME generates advisories for preparing contingency plans in agriculture based on seasonal and sub-seasonal climate outlooks that integrate forecasts, location specific hazard thresholds, and risk patterns. The climate forecast helps to analyze the risk and understand the vulnerability based on climate risk profiles so that action plans can be prepared and implemented.
Similar sophisticated expert systems could be developed for generating location-specific advisories for other sectors.
We conclude the report by providing a proposal for a 6-step approach aimed at strengthening regional coordination and collaboration between agencies and national governments across the Asia-Pacific Region to prepare for and respond to extreme climate events. Our streamlined offer-of-service will provide countries at risk from El Niño with a coordinated step-by-step plan that can be activated and implemented at the appropriate time as the event is unfolding. The different steps in the provision of services and products will be triggered by critical changes in seasonal rainfall during the monsoon cycle. The approach consists of the following six steps: 1) Provision of Regional Climate Outlooks; 2)
Provision of National Climate Outlooks; 3) Assessment of risk management options; 4) Delivery of humanitarian support; 5) Critical support during time of crisis; and 6) Post-event recovery.
- UN Office for the Coordination of Humanitarian Affairs
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