The joint World Meteorological Organization (WMO) and World Health Organization (WHO) Climate and Health Office has issued a briefing paper about health and the El Niño Southern Oscillation (ENSO) as part of a wider WHO effort to review the current health risks and responses of the El Nino event in high risk countries.
The ongoing El Niño event is one of the three strongest since 1950 and is the strongest since 1997-1998, according to WMO. It is contributing to extreme weather patterns around the world and combined with long-term climate change to fuel record global surface temperatures in 2015.
The 2015-2016 El Niño, through the associated weather and climate extremes including droughts and floods, is currently affecting the health of millions of people. The health consequences of El Niño will be felt even after the climatic peak of the event and are likely to last throughout the year. WHO estimates the health of 60 million people may be impacted by weather and climate anomalies associated with El Niño this year, generating costly burdens on health systems.
Local incidence of vector-borne and waterborne diseases, wildfire smoke exposure, and flood- and drought-related health and nutritional impacts, are climate and weather sensitive and have all been observed to be influenced by factors associated with ENSO events, according to the WHO-WMO brief.
Evidence of the association between El Niño and malaria has been found in Southern Africa, South Asia and South America and with Rift Valley fever outbreaks in the Horn of Africa.
Studies have shown El Niño events exacerbate wild fires in Brazil, Indonesia and Malaysia. In 2015, air quality became hazardous in six South East Asian countries due to wildfires worsened by El Niño-related drought, including Indonesia where a state of emergency was declared due to hazardous air quality, evacuating populations, and sending thousands to seek medical care.
Previous El Nino events have resulted in dramatic health impacts, particularly on food security in Africa. In 1991–1992, El Niño triggered the drought in southern Africa, affecting nearly 100 million people. The world food crisis of 1982–84, the most severe recorded, was linked to El Niño, including famines that struck large populations in Africa.
However, the world is better prepared for the current ongoing El Niño than any other previous event, based on lessons learnt during the strong 1997-98 El Niño, and the proactive approaches put in place by WMO, its Members and partners for monitoring and early warning of ENSO.
Regional and national climate outlooks from meteorological services predicted the advent and evolution of this El Niño many months in advance. Recent advances in ENSO prediction and the increased predictability of climate events on seasonal to interannual time scales during ENSO events can help health professionals to reliably anticipate the location and timing of ENSO-related health risks. The availability of this climate knowledge has allowed WHO to proactively raise awareness and support its regional and national offices to mobilize resources and trigger appropriate preparedness measures.
WMO will issue its next El Niño Update, based on models and expert opinion from around the world, in mid-February.
The WHO-WMO briefing paper
Details of WHO action available here
WMO animation on El Niño available here