What is El Niño and why is this year’s different?
A strengthening El Niño layered on top of decades of human-caused climate change is pushing ocean temperatures to record highs and threatening marine wildlife. El Niño is the warming phase of a natural climate pattern called the El Niño–Southern Oscillation or ENSO. The other, “cooling,” phase is La Niña.
El Niño forms when the easterly trade winds weaken and surface waters along the equatorial Pacific warm more than usual. El Niño usually brings a significantly rainier winter to California and the southern United States. It also suppresses Atlantic hurricane activity while boosting tropical storm formation in the eastern and central Pacific.
According to the National Oceanic and Atmospheric Administration (NOAA), El Niño has been underway since June 2026. NOAA forecasters warn that the current El Niño is likely to become a “super El Niño,” an exceptionally strong event in which sea surface temperatures in the tropical Pacific rise at least 2°C (3.6°F) above normal.
El Niño and human-driven ocean warming
Scientists believe the natural warming from the current El Niño is combining with decades of human-caused climate change to push ocean warming to record highs, and this one-two punch is already showing up in the data. In August 2026, the global average ocean temperature climbed to a record 21.10°C (69.98°F), according to the European Union’s Copernicus Climate Change Service (C3S). That marks the highest reading since the agency began tracking in 1979.
Our ocean absorbs 90% of the excess heat from carbon pollution and other greenhouse gases. This heat is pushing our ocean to its limits and warming it at an alarming rate. Unprecedented, human-driven ocean warming combined with a potentially historic El Niño could make 2027 a disastrous year for our climate and ocean health.
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What can we expect moving forward?
Rising ocean temperatures have a host of negative impacts, including coral bleaching, harmful algae blooms, food chain collapse and ecosystem disruption. The 2015–2016 Super El Niño set off a catastrophic domino effect where toxic algae bloomed in Pacific waters, large populations of krill, a keystone species that underpins the diets of countless marine animals died off, and the West Coast saw withering kelp forests, massive seabird die-offs, whale deaths and starving sea lion pups.
Climate change may even be making El Niño stronger, according to new research. During normal years, El Niño brings heavy rain to some regions and drought, heat waves and wildfires to others. However, the modern El Niño is more than 36% stronger than it was before the industrial era began in the mid-1800s. The strength of El Niño has increased by 16% just over the last 40 years. The climate crisis could fuel even more intense weather in this year’s El Niño.
What can we do about this?
A warmer ocean puts the whole world in hot water, figuratively and literally. There is nothing unusual about natural weather patterns like El Niño, but factors like the climate crisis and a warming ocean could be pushing these weather patterns to new extremes. Put simply, the more we rely on dirty fossil fuels, the more our ocean and marine wildlife will suffer from rising ocean temperatures. But we can change course if we act now.
Ocean Conservancy is urgently working to phase out harmful offshore oil and gas drilling, transition to clean ocean energy and evaluate emerging technologies that reduce and remove carbon pollution. We are also leading international efforts to decarbonize the shipping industry, which emits roughly 1 billion tons of greenhouse gases each year.
This work is essential, and we cannot do it alone. Take action now to help us tackle the climate crisis head-on, protect marine life and defend our ocean’s future.
Our Ocean is Sending a Warning
…and it’s time for Congress to listen. Our elected officials must take action to move away from dirty fossil fuels that exacerbate climate change and toward clean energy. Add your name now.
