Super El Niño Could Intensify Global Heat and Trigger Long-Term Climate Shifts

Climate forecasters warn that the ongoing El Niño pattern could intensify in the coming months, adding potentially unprecedented heat to an already warming planet.

El Niño is the warm phase of a naturally occurring, multiyear climate cycle known as the El Niño-Southern Oscillation (ENSO). Current climate models suggest that this year’s event could become exceptionally strong. A super El Niño may drive extreme temperatures and disruptive weather through next year, while also increasing the risk of longer-term climate damage.

Jong-Seong Kug, a professor in the Department of Earth and Environmental Sciences at Seoul National University in South Korea, studies El Niño using observational records, climate models and artificial intelligence.

Kug’s research suggests that super El Niño events can produce sudden, dramatic and potentially irreversible climate regime shifts. Live Science spoke with Kug about how these shifts occur and why the current El Niño could pose long-term risks to ecosystems and communities.

How concerned should we be about a super El Niño?

Patrick Pester: Last year, you published a study that found super El Niño events significantly increase the likelihood of potentially irreversible climate regime shifts. With a super El Niño now looking very likely, how concerned should we be?

Jong-Seong Kug: We should be concerned, but not alarmist. Our study does not show that every super El Niño inevitably causes a climate regime shift. Instead, a powerful El Niño can push an already stressed climate system beyond a critical threshold. When a system is close to that threshold, intense natural forcing may trigger an irreversible change.

Forecasts indicate that a very strong El Niño is increasingly likely later this year. Scientists should closely monitor vulnerable regions already facing severe warming, drought, ecosystem degradation and ocean stress.

Could El Niño trigger an Amazon rainforest tipping point?

PP: What type of climate regime shift concerns you most?

J-S K: I am particularly concerned about persistent changes in major ecosystems, including the possibility that the Amazon rainforest could shift toward a much drier and more degraded state. The Amazon was once a savannah region, and current conditions suggest that parts of the forest may be approaching a critical tipping point.

As the Amazon becomes hotter and drier, forest dieback could weaken or even reverse its role as a carbon sink. If the forest can no longer absorb carbon dioxide and instead releases stored carbon, it could become a carbon source and amplify global warming long after the El Niño event ends.

How can communities prepare for extreme weather?

PP: Can anything be done to reduce the effects of extreme climate and weather events in the coming months?

J-S K: We cannot stop El Niño, but we can significantly reduce its effects on people and ecosystems. Governments should use high-resolution forecasts to strengthen heat-health plans, improve water and food management, and prepare for floods and wildfires.

Over the longer term, rapidly cutting greenhouse gas emissions is essential. Every additional degree of global warming increases the chance that an extreme natural event will push vulnerable ecosystems past a point of lasting damage.

PP: Do you think greenhouse gas emissions are likely to decline, given current conditions?

J-S K: I don’t think so. It is very difficult.

Could geoengineering reduce global temperatures?

PP: Where does that leave us?

J-S K: There are additional technologies that could be considered if the climate reaches a critical point. Have you heard about climate engineering, such as stratospheric aerosol injection, which would reflect some solar radiation back into space?

There are two broad approaches to climate engineering. The first is carbon removal, including technologies such as direct air capture, which removes carbon dioxide from the atmosphere. The second is solar radiation management, which aims to reflect more sunlight away from Earth’s surface.

Stratospheric aerosol injection would attempt to cool the planet by releasing reflective particles into the upper atmosphere. The proposed approach is similar to the natural cooling effect of major volcanic eruptions. After a large eruption, global average temperatures can temporarily fall by about 0.6 degrees Celsius, or 1 degree Fahrenheit, because of volcanic aerosols in the atmosphere.

However, solar geoengineering carries many potential side effects. Some are known, while others remain uncertain. Artificially lowering global temperatures could alter rainfall patterns, causing droughts or floods in different countries. That raises difficult questions about responsibility, compensation and climate inequality.

Any form of climate intervention would require broad international cooperation and agreement among nations.

Super El Niño is developing in an exceptionally warm world

PP: Is there anything else you’d like to add?

J-S K: This year’s super El Niño is developing against a backdrop of exceptionally high global temperatures. We are already seeing widespread heat waves, so not every extreme event can be attributed directly to El Niño.

However, El Niño is expected to intensify toward the end of the year, increasing the risk of extreme heat, heavy rainfall, droughts and other disruptive weather in many regions. Preparation is essential.

Editor’s note: This interview has been edited and condensed for clarity.