Analysis of ENSO Phase Transition and Implications for Sustainable Development Goals

1.0 Executive Summary

This report analyzes the recent formation of a La Niña event in the tropical Pacific, as confirmed by an official advisory from the National Oceanic and Atmospheric Administration (NOAA). It assesses the projected meteorological impacts for the 2025-2026 winter season and examines the long-range forecast indicating a significant reversal to an El Niño phase in 2026. The analysis is framed within the context of the United Nations Sustainable Development Goals (SDGs), highlighting the critical role of climate forecasting in advancing global targets related to climate action (SDG 13), food security (SDG 2), and sustainable communities (SDG 11).

2.0 Current State: La Niña Formation and Official Advisory

2.1 Oceanic and Atmospheric Indicators

The El Niño-Southern Oscillation (ENSO) is a critical driver of global climate variability. A transition to its cold phase, La Niña, has been confirmed for the 2025-2026 season.

• Sea Surface Temperatures (SST): Ocean temperature anomalies in the central-eastern equatorial Pacific have dropped below the -0.5°C threshold, officially initiating a La Niña event.
• Subsurface Conditions: A substantial pool of cold water has been observed at depths of up to 200 meters, created by enhanced oceanic upwelling. This subsurface cold reservoir is expected to sustain the event through the winter.
• Atmospheric Response: The atmospheric component, known as the Walker Circulation, has strengthened. This is characterized by higher atmospheric pressure over the central Pacific and lower pressure over the western Maritime Continent, a classic La Niña signature.

2.2 Official Confirmation

The Climate Prediction Center (CPC) of NOAA has issued a La Niña advisory. The official outlook states a high probability that these conditions will persist through the Northern Hemisphere’s winter (December 2025 – February 2026), with a likely transition to ENSO-neutral conditions in early 2026.

3.0 Projected Impacts of La Niña (Winter 2025-2026) and SDG Implications

The atmospheric changes induced by La Niña have predictable consequences for regional weather patterns, which directly impact progress toward several SDGs.

3.1 North American Weather Patterns

1. Jet Stream Displacement: A strong blocking high-pressure system in the North Pacific is anticipated, which will divert the polar jet stream southward over the northern United States and southern Canada.
2. Temperature and Precipitation Anomalies: This pattern typically results in colder-than-average conditions and increased snowfall potential across the northern tier of the United States and Canada, while the southern United States experiences warmer and drier conditions.

3.2 Relevance to Sustainable Development Goals

• SDG 13 (Climate Action): The La Niña event underscores the reality of climate variability. Accurate forecasting and understanding its impacts are fundamental to developing effective climate adaptation strategies and strengthening resilience to climate-related hazards.
• SDG 11 (Sustainable Cities and Communities): Increased frequency of cold air outbreaks and heavy snowfall in northern regions demands robust municipal preparedness. This includes managing energy demand, ensuring transportation infrastructure remains functional, and mitigating risks to vulnerable populations, all key targets of SDG 11.
• SDG 6 (Clean Water and Sanitation): Altered precipitation patterns, particularly changes in snowpack accumulation and melt, directly affect water resource management for agriculture, industry, and human consumption.
• SDG 7 (Affordable and Clean Energy): Colder winters in densely populated northern regions can strain energy grids. This highlights the need for resilient and efficient energy systems to ensure reliable access during periods of peak demand.

4.0 Forecasted Reversal to El Niño in 2026 and Global SDG Challenges

Long-range climate models and atmospheric precursors indicate a high probability of a rapid transition to an El Niño phase in mid-to-late 2026. This cyclical shift will overhaul global weather patterns and present a different set of challenges to sustainable development.

4.1 Leading Indicators of an El Niño Event

• Long-Range Model Consensus: Ensemble forecasts from major climate centers, including the ECMWF, show a decisive shift toward positive (warm) SST anomalies in the ENSO region beginning in Spring 2026.
• Atmospheric Precursors: The forecast development of a high-pressure system in the North Pacific during the upcoming winter is a known precursor pattern that weakens trade winds and facilitates the buildup of warm water, initiating an El Niño.

4.2 El Niño’s Global Impact on SDG Targets

The warm phase of ENSO has profound and far-reaching consequences, particularly for food systems and vulnerable economies.

1. SDG 2 (Zero Hunger): El Niño significantly alters global rainfall and temperature patterns, leading to widespread impacts on agricultural productivity.
   • It can cause droughts in Southeast Asia, Australia, and parts of Africa, leading to crop failures and threatening food security.
   • Conversely, it can increase rainfall in parts of the Americas, potentially benefiting some crop yields while increasing flood risk in others. Understanding these impacts is crucial for global food supply management and achieving Zero Hunger.
2. SDG 1 (No Poverty) & SDG 8 (Decent Work and Economic Growth): Climate-induced disruptions to agriculture, fisheries, and other primary economic sectors can disproportionately harm developing nations, potentially reversing progress on poverty reduction and hindering economic growth.
3. SDG 14 (Life Below Water) & SDG 15 (Life on Land): The significant warming of ocean waters during an El Niño can cause mass coral bleaching events and disrupt marine ecosystems. On land, resulting droughts and floods can devastate terrestrial ecosystems and biodiversity.

5.0 Conclusion: Integrating Climate Science for Sustainable Development

The forecast transition from La Niña in 2025-2026 to a potential El Niño in 2026-2027 provides a critical window for proactive planning. Long-range forecasting is an indispensable tool for mitigating risks and aligning national and international policies with the Sustainable Development Goals. By integrating these climate insights, governments and organizations can enhance disaster preparedness (SDG 11, SDG 13), stabilize food systems (SDG 2), and build a more resilient future in the face of climate variability.

Analysis of Sustainable Development Goals in the Article

1. Which SDGs are addressed or connected to the issues highlighted in the article?

The article on La Niña and El Niño weather phenomena connects to several Sustainable Development Goals (SDGs) by discussing large-scale climate patterns, their environmental monitoring, and their socio-economic impacts.

• SDG 2: Zero Hunger: The article explicitly mentions how El Niño affects global weather patterns, which in turn has a significant impact on “crop yields and its effect on food production.” This directly relates to food security and the sustainability of agricultural systems.
• SDG 11: Sustainable Cities and Communities: The forecast of extreme weather events, such as “colder temperatures and winter storms” and “cold air outbreaks,” is directly relevant to the resilience of communities and infrastructure. Preparing for these events is crucial for reducing their impact on human settlements.
• SDG 13: Climate Action: The entire article is centered on understanding and forecasting climate-related phenomena (ENSO cycle). It discusses strengthening resilience and adaptive capacity by providing early warnings (“official advisory by NOAA”) about climate-related hazards like severe winter weather, which is a core component of climate action.
• SDG 14: Life Below Water: The article’s analysis is fundamentally based on oceanic conditions. It details the monitoring of “ocean temperature anomaly,” “upwelling,” and the formation of a “large cold pool” in the Pacific Ocean. These elements are critical to understanding the health and dynamics of marine ecosystems.

2. What specific targets under those SDGs can be identified based on the article’s content?

Based on the issues discussed, the following specific SDG targets can be identified:

1. Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters in all countries.
   • The article contributes to this target by explaining the mechanisms of La Niña and El Niño and forecasting their impacts on winter weather. The issuance of an “official La Niña advisory” by NOAA is a direct action to help regions like North America and Europe prepare for and adapt to potential hazards like increased snowfall and cold air outbreaks.
2. Target 2.4: By 2030, ensure sustainable food production systems and implement resilient agricultural practices that increase productivity and production… and strengthen capacity for adaptation to climate change, extreme weather, drought, flooding and other disasters.
   • The article highlights the connection between El Niño and “global changes in pressure and rainfall patterns,” which affects “crop yields.” By forecasting these events, it provides crucial information for the agricultural sector to adapt practices and build resilience against climate-driven impacts on food production.
3. Target 11.5: By 2030, significantly reduce the number of deaths and the number of people affected and substantially decrease the direct economic losses… caused by disasters.
   • The long-range forecasting of a “disrupted jet stream pattern,” increased “snowfall potential,” and a higher chance of a “Sudden Stratospheric Warming (SSW) event” serves as an early warning system. This information allows communities and governments to take preparatory measures to mitigate the potential damage and human impact of severe winter storms and extreme cold.
4. Target 14.2: By 2020, sustainably manage and protect marine and coastal ecosystems to avoid significant adverse impacts, including by strengthening their resilience.
   • The article’s detailed monitoring of “ocean surface temperatures” and sub-surface conditions in the Pacific Ocean is essential for understanding the state of this massive marine ecosystem. The data on temperature anomalies and upwelling processes are fundamental to managing and protecting marine life from the effects of large-scale climate variability.

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

The article mentions or implies several indicators that can be used to track progress towards the identified targets:

• Ocean Temperature Anomaly: This is a primary, explicitly mentioned indicator used throughout the article. The text specifies the threshold for a La Niña event (“dropping below the -0.5 degrees anomaly”) and uses data from NOAA to track these changes. This indicator is crucial for monitoring conditions related to SDG 13 (Climate Action) and SDG 14 (Life Below Water).
• Atmospheric Pressure Patterns: The article discusses and shows images of high and low-pressure anomalies over the Pacific. The analysis of the “Walker Circulation” and the identification of a “strong blocking high-pressure system” are used to forecast weather impacts, serving as an indicator for early warning systems under SDG 11 and SDG 13.
• Crop Yield Variations: The article explicitly refers to the “impact of El Niño on crop yields and its effect on food production” and includes a graphic illustrating this. Changes in crop yields in different regions serve as a direct indicator for measuring the impact of climate events on food security (SDG 2).
• Frequency and Intensity of Extreme Weather Events: The article discusses the increased “snowfall potential” and the “60-75% chance of producing a Sudden Stratospheric Warming (SSW) event” during a La Niña winter. Tracking the occurrence of these events serves as an indicator of climate-related hazards and the need for disaster risk reduction (SDG 11 and SDG 13).

4. Summary Table of SDGs, Targets, and Indicators

Source: severe-weather.eu