Summary of Key Points
Recently, global sea surface temperatures have reached record highs, surpassing those of the same periods in 2023 and 2024. This is mainly due to the approaching El Niño phenomenon in the equatorial Pacific Ocean, which could be one of the strongest in several decades. The resulting weather patterns are expected to be more extreme over the coming months, with occurrences of heavy rainfall, droughts, and heatwaves. It will also have detrimental effects on marine ecosystems and coastal economies. The World Meteorological Organization (WMO) is urging everyone to prepare in advance.
How Hot Have the Sea Surface Temperatures Really Become?
Data from two authoritative organizations confirms that this year’s sea temperatures are exceptionally high:
- The Copernicus Climate Service (C3S) reported a sea surface temperature of 20.86°C on June 21, which is 0.03°C higher than the same period in 2023 and 2024 (20.83°C).
- The Copernicus Marine Environment Monitoring Service (CMEMS) reported an even higher temperature of 21.0°C on the same day, a 0.1°C increase from the previous year.
This is not a localized phenomenon; it affects the entire globe, especially in the non-polar regions between 60°N and 60°S, where June temperatures have reached record levels.
Why Are the Sea Surface Temperatures Suddenly So High? El Niño Is to Blame
The record-breaking temperatures are not accidental and are mainly due to two factors:
1. The Arrival of El Niño: The waters in the central and eastern equatorial Pacific Ocean are warming, and the deep-sea temperatures are more than 6°C higher than usual. This heat will gradually rise to the surface, causing the temperature to increase.
2. Preceding Conditions: The North Pacific has experienced record-high temperatures in the past few months, which have further contributed to the overall rise in global sea temperatures.
Both organizations emphasize that this situation was anticipated, as El Niño itself is a natural phenomenon that affects both the atmosphere and the oceans.
How Strong Could This El Niño Be?
According to forecasts:
- The WMO estimates an 80% chance of El Niño occurring between June and August, with a probability of over 90% by November.
- Most models predict that this El Niño will be at least moderate in intensity, and it could potentially develop into a strong El Niño, reaching levels not seen in decades.
The El Niño phenomena in 2023-2024 were already among the five strongest on record, and they contributed to global temperature records in 2024. This current event could be even more severe.
What Problems Could Rising Sea Surface Temperatures and El Niño Cause?
These high temperatures are not just a minor inconvenience; they can trigger a series of problems:
1. Increased Extreme Weather: Warmer sea surfaces provide more energy for storms, leading to more frequent heavy rainfall and floods. El Niño will also alter global weather patterns, causing some areas to experience greater droughts (e.g., Southeast Asia) and others to face more severe flooding (e.g., South America).
2. Damage to Marine Ecosystems: Rising sea temperatures can trigger marine heatwaves, which can cause coral bleaching and death, disrupt fish populations, and impact fishermen’s livelihoods.
3. Sea Level Rise: As water heats up, it expands, leading to higher sea levels. Combined with glacier melting, coastal areas are at greater risk of flooding.
4. Intensified Land Heatwaves: Marine heatwaves can transfer their effects to land, making heatwaves more frequent and intense.
WMO’s Warning: Prepare for a Strong El Niño
WMO Secretary-General Petteri Taalas stated, “We need to prepare for a potentially strong El Niño.” Here are some steps to take:
- Drought Mitigation: Stockpile water resources in advance and adjust agricultural practices.
- Flood Prevention: Strengthen dams and improve urban drainage systems.
- Heatwave Protection: Prepare measures to protect the elderly and children from heat-related illnesses.
- Fishermen and Coastal Businesses: Plan ahead to minimize the impact on marine ecosystems and their livelihoods.
In summary, the record-breaking sea surface temperatures are a sign of climate change and El Niño. The coming months may bring more extreme weather events, so it’s important to stay vigilant.