CommentaryImagine the vast Pacific, with its rhythm of trade winds and currents, warming as though a fever were spreading across its surface. Fishermen along the coasts of Peru and Ecuador notice their nets returning empty, rains arrive where deserts once stood, and drought grips lands that once thrived. This recurring phenomenon is known as El Niño—Spanish for “little boy.” It begins with unusually warm surface waters in the central and eastern tropical Pacific and disrupts weather patterns across continents.
But El Niño is more than a scientific curiosity. Its waves ripple through societies, economies, and governance structures. Crops fail, communities are displaced, and fragile ecosystems collapse. The World Meteorological Organization (WMO) forecasts a nearly 100% likelihood that El Niño will persist through February 2027. The US National Oceanic and Atmospheric Administration (NOAA) forecasts a greater-than-90% chance of a very strong event during Northern Hemisphere fall and winter 2026–27. Under Article 23 of the International Law Commission (ILC) Articles on Responsibility of States for Internationally Wrongful Acts (ARSIWA), force majeure requires an irresistible force or unforeseen event beyond the state’s control that makes performance materially impossible.
Thus, El Niño is both a story of the ocean’s power and a test of state responsibility. It challenges states to uphold their duties under international environmental law, protect fundamental rights to food, water, and health, and ensure that governance does not falter when the climate shifts.
How El Niño Develops
El Niño is caused by a combination of oceanic and atmospheric changes that disrupt the normal climate balance. It begins with the Pacific Ocean warming, when surface waters in the central and eastern Pacific become unusually warm. This warming weakens or reverses the trade winds that usually push water westward, allowing it to spread eastward instead. As a result, rainfall and temperature patterns shift dramatically across different regions. The warming also alters atmospheric circulation, creating storms in new areas while leaving others in drought.
How El Niño Affects Communities
The “super El Niño” is already reshaping global weather in ways that highlight its far-reaching consequences. Its effects vary by location and season, and the strength of an El Niño event alone does not determine the severity of its local impacts.
El Niño tends to suppress Atlantic hurricane activity while increasing hurricane activity in the eastern and central Pacific. WMO identifies agriculture, health, energy, and water resources as sectors requiring preparation for El Niño’s impacts. Humanitarian consequences such as displacement, water scarcity, and health emergencies also follow, underscoring that El Niño is not only a climate phenomenon but a governance challenge, requiring states to prepare for disasters, protect human rights, and cooperate under international environmental law.
When Governments Can Be Held Responsible
El Niño does not automatically establish a force majeure defense under international law.
The International Court of Justice (ICJ) describes due diligence as a standard for assessing a state’s conduct in light of its circumstances. States must exercise due diligence to prevent significant environmental harm from activities within their jurisdiction or control, a duty reflected in Principle 21 of the Stockholm Declaration, 1972 and later reaffirmed under Principle 2 of the Rio Declaration on Environment and Development, 1992. These principles establish that states have the sovereign right to exploit their own resources but also the responsibility to ensure that activities within their jurisdiction or control do not cause environmental damage to other states or areas beyond national jurisdiction.
When states fail to act with appropriate diligence to prevent predictable harm and danger, state responsibility for internationally wrongful acts can be triggered. A failure to prepare can engage state responsibility where it breaches an applicable international obligation. Negligence in managing water infrastructure, food systems, or health services during El Niño undermines rights to food, clean water, housing, and health care. El Niño is not a divine surprise. It is a forecasted crisis, and governments are legally bound to act.
In its 2025 climate advisory opinion, the ICJ affirmed that adaptation obligations under the Paris Agreement are assessed against a due diligence standard. Article 48 of ARSIWA permits a noninjured state to invoke responsibility for breaches of obligations protecting a collective interest of a group to which it belongs, or owed to the international community as a whole. States entitled to invoke responsibility under Article 48 may demand cessation of a continuing internationally wrongful act.
How do we know when an internationally unlawful act is committed? Under Article 2 of ARSIWA, an internationally wrongful act arises when an act or omission (a) is attributable to the state under international law, and (b) constitutes a breach of an international obligation of the state. In this case, where states fail to abide by their obligations stipulated under relevant international environmental laws in order to mitigate their contribution to climate change, they can be held liable.
What Governments Must Do to Prepare
The ICJ identifies early warning systems and resilient infrastructure among measures that can help meet adaptation obligations. Practical actions include strengthening roads and buildings, managing water supplies to reduce drought impacts, and protecting farms and food chains. Since El Niño threatens basic human rights like the right to life, food, and water, states must plan ahead to protect people, especially those most at risk. However, not all countries have the same resources to do this. Wealthier countries can afford advanced technology and stronger infrastructure, while resource-constrained countries may struggle. International cooperation is also a legal duty. Under the Paris Agreement, developed-country parties must provide financial resources to assist developing-country parties with mitigation and adaptation.
El Niño is a natural climate phenomenon for which forecasts give governments time to prepare. Because it is predictable, states cannot hide behind excuses of surprise. International law requires them to act with due diligence: to prepare infrastructure, manage water and food supplies, and protect people’s basic rights to life, food, and water. While wealthier nations may have more resources to respond, resource-constrained countries face greater risks and need support. In the end, El Niño is a test of responsibility: whether states use the rule of law to protect their citizens and work together, or whether they allow predictable harm to become avoidable tragedy.
Cecile Akoeley Attiogbe Atayi is a student in her final year of study at the University of Cape Coast Faculty of Law in Ghana. She is also a staff writer and editor at JURIST.
