Climate Change May Be Strengthening El Niño as Ancient Coral Records Reveal an Unprecedented Shift

August 28, 2026: Scientists have uncovered new evidence that rising global temperatures are making one of Earth’s most influential climate patterns more intense, raising concerns about the future frequency and severity of extreme weather events around the world.

A new study using centuries-old and fossilized coral from the Galápagos Islands suggests that El Niño events during the past four decades have been nearly 40% stronger than those experienced during the pre-industrial period. Researchers say the recent intensity is exceptional when compared with the previous millennium.

The findings provide a longer historical perspective on El Niño and strengthen the evidence that human-caused warming is changing the behaviour of this naturally occurring climate phenomenon.

Coral Becomes a Natural Climate Archive

One of the biggest difficulties in studying El Niño is the limited length of modern instrumental records.

Reliable measurements of ocean temperatures extend back only a relatively short period compared with the timescale of Earth’s climate system.

To overcome that limitation, researchers turned to coral.

Corals grow by gradually adding layers to their skeletons. The chemical composition of those layers preserves information about the temperature of the surrounding seawater at the time the coral grew.

By studying both living and ancient corals in the Galápagos, scientists were able to reconstruct changes in eastern Pacific temperatures over approximately 1,000 years.

Why the Galápagos Are So Important

The Galápagos Islands occupy a particularly valuable position for studying El Niño.

The archipelago lies in the eastern equatorial Pacific, an area strongly affected by the warming and cooling associated with the El Niño-Southern Oscillation.

When El Niño develops, warm water spreads eastward across the tropical Pacific, changing atmospheric circulation and rainfall patterns.

The resulting effects can extend far beyond the Pacific.

Because the Galápagos experience pronounced temperature changes during these events, their corals effectively preserve a natural record of El Niño’s past behaviour.

What the Researchers Found

The researchers examined coral samples from the Galápagos and analysed chemical indicators linked to seawater temperature.

Their reconstruction showed that the average strength of El Niño events during the most recent 40-year period was substantially greater than during the pre-industrial era.

The study estimated that eastern-Pacific ENSO variability is about 37% higher than during the pre-industrial period. Other descriptions of the same research round the increase to nearly 40%.

The researchers also found that the strongest El Niño events of the past four decades were more intense than those recorded in the previous thousand years represented by their coral archive.

A Climate Pattern With Global Consequences

El Niño is not simply a regional warming event.

It is part of the larger El Niño-Southern Oscillation, or ENSO, a natural interaction between the tropical Pacific Ocean and atmosphere.

During El Niño, warmer-than-normal waters develop across parts of the equatorial Pacific.

That change can reorganize atmospheric circulation and influence weather patterns thousands of kilometres away.

Depending on the location, El Niño can contribute to unusually heavy rainfall, flooding, drought, heatwaves and changes in agricultural conditions.

It can also affect marine ecosystems and fisheries.

Stronger El Niño Could Mean Greater Weather Risks

If El Niño events continue becoming stronger as the planet warms, their ability to produce extreme weather could increase.

Communities already exposed to climate-related hazards could face additional pressure.

Agricultural regions may experience altered rainfall patterns, while areas vulnerable to flooding could face periods of unusually heavy precipitation.

Other regions may encounter drought conditions.

The economic consequences can spread through food markets, energy systems, transportation networks and disaster-response budgets.

The Current El Niño Adds Urgency

The new research comes as a strong El Niño event is developing in the tropical Pacific.

Satellite observations from NASA showed that the 2026 event was continuing to strengthen in June after El Niño conditions emerged earlier in the year.

That makes the new long-term evidence particularly relevant.

Scientists are watching the current event while also trying to understand whether the unusually strong El Niños of recent decades represent a temporary fluctuation or part of a longer-term response to global warming.

Human-Caused Warming Is the Key Concern

The researchers compared the coral-derived record with modern observations and climate-model simulations.

They found that the recent increase in El Niño strength is difficult to explain through natural climate variability alone.

The timing of the intensification also broadly follows the rise in global temperatures.

The study therefore provides evidence supporting the idea that human-driven warming is altering the behaviour of ENSO.

However, scientists continue to emphasize that climate systems are complex and that individual El Niño events can vary considerably.

Why the 1,000-Year Record Matters

A major strength of the research is its historical perspective.

A few decades of measurements are not always enough to determine whether an unusual climate event represents a genuine long-term change or simply natural variability.

The coral record allows scientists to compare modern conditions with a much broader range of past climate behaviour.

The finding that recent El Niños stand out against approximately a millennium of earlier records makes the recent change particularly noteworthy.

Climate Models Face a New Test

The findings could also help scientists improve climate models.

Climate models have produced differing projections for how ENSO will respond to continued global warming.

One reason for the uncertainty is the limited historical data available for testing those models.

Long-term coral records provide an independent benchmark.

Researchers can compare modelled ENSO behaviour with evidence from the past and determine which models better reproduce the observed changes.

That could improve projections of future climate risks.

Effects Could Reach Food Security

El Niño can have major consequences for agriculture.

Changes in rainfall and temperature can affect crop yields across different parts of the world.

A stronger event could intensify those disruptions.

Food-producing regions may face drought, excessive rainfall or unusual heat at different stages of the growing season.

Because global food markets are interconnected, a major production shock in one region can influence prices and supplies elsewhere.

This makes El Niño an economic issue as well as a climate-science problem.

Marine Ecosystems Face Additional Pressure

The Pacific Ocean is also home to highly sensitive marine ecosystems.

El Niño changes ocean temperatures and can disrupt nutrient-rich upwelling along parts of the eastern Pacific.

That can affect plankton, fish populations, seabirds and other marine species.

The Galápagos ecosystem is particularly famous for its biodiversity and its dependence on ocean conditions.

More intense El Niño events could therefore create additional stress for ecosystems already facing warming oceans and other environmental pressures.

Not Every Extreme Event Is Caused by El Niño Alone

Scientists caution against attributing every extreme weather event directly to El Niño.

Weather outcomes are influenced by numerous factors, including atmospheric circulation, ocean temperatures, regional geography and long-term climate change.

El Niño can increase the likelihood or intensity of certain conditions, but it does not determine exactly what will happen everywhere.

The new research instead points to a broader concern: a warmer planet may be changing the baseline behaviour of a climate system that already produces major fluctuations.

Preparing for a More Volatile Climate

The findings underline the importance of improving early-warning systems.

Better forecasting can give governments, farmers, emergency agencies and communities additional time to prepare for potential droughts, floods and heatwaves.

Investments in climate monitoring, food-storage systems, water management and disaster preparedness could reduce the impact of future extreme events.

At the same time, reducing greenhouse-gas emissions remains central to limiting further warming.

A Warning Written in Coral

The ancient coral records provide an unusual message from the past.

For centuries, the skeletons of corals quietly recorded changes in Pacific Ocean temperatures.

Scientists have now decoded those records and found that recent El Niño behaviour stands out from much of the previous millennium.

The result does not mean every future El Niño will necessarily be stronger than the last.

But it does suggest that global warming may be changing the natural climate system in ways that increase the potential for extreme events.

As the 2026 El Niño continues to develop, researchers will be watching the Pacific closely.

The combination of modern satellite observations and ancient natural archives could provide a clearer picture of where the world’s climate is heading—and how societies can prepare for the risks ahead.

Note: The study provides evidence of a relationship between recent El Niño intensification and global warming, but researchers continue to investigate the complex mechanisms connecting climate change and ENSO variability.