Oceans are heating up as El Niño weather patterns return

Scientists worldwide have begun to fear extreme ocean water temperatures, worrying that it will add to the global warming of the Earth. 

The climate phenomenon known as "El Niño" has caused oceans to reach the highest temperatures in recorded history. Scientists still do not fully understand what caused it, but they predict that ocean temperatures will continue to rise. 

During El Niño, winds blowing west along the equator slow down, and warm water is pushed east, creating warmer surface ocean temperatures.

"El Niño is normally associated with record-breaking temperatures at the global level. Whether this will happen in 2023 or 2024 is not yet known, but it is, I think, more likely than not," said Carlo Buontempo, director of the EU's Copernicus Climate Change Service.

Rising ocean temperatures are likely to cause increased rates of marine animal deaths, according to scientists. What is more, weather patterns will reach further extremes and sea levels will rise worldwide. 

Although overall ocean temperatures have reached a new record high this month, the increase was particularly extreme in certain places. In March, water temperatures off the east coast of North America were 13.8 degrees (Celcius) higher than the 1981-2011 average. 

According to researcher Karina von Shukman: "The climate has doubled in [rate of] warming in the last 15 years. I don't want to make a statement about climate change or natural changes - we still don't know. But we do see change."

Pollution from ships also has a significant impact on ocean heat levels. In 2020, the International Maritime Organization implemented new regulations to reduce sulfur content in the fuel used by ships. This had a rapid, noticeable effect, reducing gas particles released into the atmosphere. 

What are the effects of ocean warming?

In recent years, the average surface temperature of oceans worldwide has increased by nearly one degree Celsius. For reference, average temperatures on land have increased by more than 1.5 degrees Celsius since the industrial revolution. It takes much more energy to heat water than land, as oceans absorb heat deep below the surface. 

This small increase has significant consequences for marine flora and fauna. Frequent heat waves are particularly harmful to coral reefs. And more extreme weather patterns lead to natural disasters like tsunamis and hurricanes which are destructive to both marine life and life on land. 

Finally, the rising temperatures are causing a rise in sea level as the warm water accelerates the melting of the glaciers. 

El Niño returns in 2023-2024

Climate models suggest a return to El Niño conditions in the late boreal summer, and the possibility of a strong El Niño developing towards the end of the year, Buontempo said.

The world's hottest year on record so far was 2016, coinciding with a strong El Niño - although climate change has fuelled extreme temperatures even in years without the phenomenon.

The last eight years were the world's eight hottest on record - reflecting the longer-term warming trend driven by greenhouse gas emissions.

Friederike Otto, senior lecturer at Imperial College London's Grantham Institute, said El Niño-fuelled temperatures could worsen the climate change impacts countries are already experiencing - including severe heatwaves, drought and wildfires.

"If El Niño does develop, there is a good chance 2023 will be even hotter than 2016 – considering the world has continued to warm as humans continue to burn fossil fuels," Otto said.

The Environment and Climate Change portal is produced in cooperation with the Goldman Sonnenfeldt School of Sustainability and Climate Change at Ben-Gurion University of the Negev. The Jerusalem Post maintains all editorial decisions related to the content.

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