The super El Niño is more than a climate shock – it’s a health one, too

The 2026–27 El Niño climate cycle is shaping up to be one of the strongest in more than a century. But the threat stretches beyond the immediate impacts of bad weather.

El Niño is part of a cycle in Earth’s climate that is linked to warmer than usual waters in the Pacific Ocean. Every few years, it brings droughts or floods to different regions. This year, sea surface temperatures in the eastern Pacific have already exceeded those of the four other recorded very strong El Niño events that have occurred in the past 50 years. Countries such as Panama and Indonesia are now experiencing low rainfall, and Brazil is bracing itself for wildfires. Such events have also historically had long-lived effects on economies and health. For example, the 1982–83 El Niño event resulted in a global income loss of US$4.1 trillion; for the 1997–98 one, the figure was $5.7 trillion1. And life expectancy at birth in ten (relatively wealthy) Pacific Rim countries was lowered by 0.54 years during the earlier event and by 0.37 years during the later one, relative to what would otherwise have been expected2. El Niño exposure has also been linked to childhood undernutrition, with measurable effects on height and weight3.

The latest El Niño’s effects on different places will thus depend not just on the regions’ resilience to extreme weather, but on the resilience of their food, agriculture and health systems. The World Health Organization (WHO)4 and other global organizations are aware of these risks. However, climate change, food insecurity and infectious diseases are often considered separately, despite being interdependent5.

The worst El Niño in recorded history is brewing — here’s how governments must prepare

We argue that the risk of catastrophe does not lie solely with the strength of this El Niño, but rather with how it interacts with other crises and local institutions. Comparatively little attention has been given to what happens when El Niño disrupts food supplies, affects what people eat and potentially changes their exposure to infectious disease.

And the latest El Niño is occurring at a time when global food systems are under pressure. Ongoing wars in Ukraine and Iran have disrupted agricultural production and trade, and fertilizers are in short supply. In isolation, many countries could withstand a major El Niño, but the combined effect of several shocks could overwhelm that resilience.

These interactions might also create health risks that are less obvious. Food shortages and changes in relative prices can alter what people eat and where they obtain their food from, potentially increasing contact with animals carrying zoonotic diseases. We argue that understanding how climate, food insecurity and infectious-disease risks interact is essential to anticipating the wider health consequences of the coming El Niño.