El Nino: A phenomenon supercharged by climate change

Anchovies are an unlikely bellwether for a building climatic event, but their disappearance from the coast of South America is heralding one of the biggest El Ninos in living memory.

These small fish usually live in colossal shoals along the Pacific coast of South America, feeding in the cold, nutrient-rich waters. Fishermen in Peru and Chile eagerly await the fishing season every year, but every now and then, it does not come as planned. This is one of those years.

Some years the easterly trade winds in the Pacific weaken or even reverse. The trigger for this remains uncertain, but it causes a warm ocean current to flow east to the coast of South America. This replaces the nutrient-rich cold water, causing the anchovies to disappear.

Because the warm waters arrive around Christmas time, Peruvian fishermen named the phenomenon El Nino de Navidad (The Christmas Child).

The impact of El Nino, a natural weather pattern, spreads much further than South America, and can bring drought or floods to millions in affected areas. This year it comes supercharged by climate change, which is worrying many scientists, governments and aid workers.

Stephanie Roe, lead climate scientist with the World Wildlife Fund (WWF), told Al Jazeera that this “super El Nino” is a stark reminder of how climate change can intensify pressures on both people and the natural world.

“El Nino can bring devastating climate extremes on its own, but it’s unfolding today on a much warmer planet, increasing the likelihood that heat, drought, floods and fires will push communities and ecosystems beyond anything they have experienced before,” Roe said.

As it develops in the Pacific, this year’s El Nino is combining with an ongoing, massive marine heatwave, further adding to the impacts of human-induced global warming. Its effects will be felt through food systems and biodiversity, impacting the livelihoods of fishermen and farmers, and the billions around the world reliant on the agricultural industry for their food.