The usual sweltering summers in Pakistan are poised to become even more devastating this year as the El Niño weather pattern takes hold over the equatorial Pacific waters. El Niño and La Niña are oceanic-atmospheric phenomena that alternately shift sea surface temperatures between the eastern and western Pacific. Collectively known as the El Niño–Southern Oscillation (ENSO), these patterns carry far-reaching consequences across the globe.
Understanding ENSO and Its Phases
The complete ENSO cycle unfolds across three phases: neutral, El Niño, and La Niña. During the neutral phase, trade winds push warm water westwards, keeping the central and eastern Pacific relatively cool. The resulting atmospheric convection over the western Pacific drives the formation of cumulonimbus clouds and generates rainfall. El Niño disrupts this balance by weakening the trade winds, allowing warm water to accumulate in the central and eastern Pacific. Convective activity consequently shifts eastwards, bringing heavy rainfall to the Americas while depriving Australia and Asia of their usual precipitation. La Niña, by contrast, intensifies the trade winds, reinforcing convection over Asia and Australia while cooling the central and eastern Pacific. Both phenomena recur every two to seven years and typically persist for nine to twelve months.
Forecast for a Strong El Niño Event
Current indicators point strongly towards an intense El Niño event. The National Oceanic and Atmospheric Administration (NOAA) places the probability of a strong El Niño at two in three, with conditions expected to strengthen through winter. The Niño 3.4 index, which measures the three-month average sea surface temperature anomaly against long-term baselines, serves as a key diagnostic tool; readings exceeding 1.5°C above average signal a strong event. Forecasts from NOAA, the Bureau of Meteorology (BoM), and the European Centre for Medium-Range Weather Forecasts (ECMWF) are converging on the probability of a strong El Niño event.
Impact on Pakistan's Monsoon and Agriculture
Pakistan's summers are ordinarily defined by monsoon rainfall, which also governs the growing cycles of key crops. Monsoon systems reach Pakistan through two corridors: south-eastern winds carrying moisture from the Bay of Bengal enter through the Himalayan foothills, feeding cities such as Lahore, Rawalpindi, Sialkot, and Jhelum; and south-western winds from the Arabian Sea form a secondary stream of precipitation. The monsoon's driving mechanism is the differential heating between land and ocean. Land warms faster, creating a low-pressure zone that draws moist oceanic air inland, where it rises and condenses into rainfall. El Niño fundamentally disrupts this mechanism. Warming the central and eastern Pacific, it creates a competing low-pressure zone far out at sea, effectively diverting the moist air that would otherwise rise over the Asian landmass. The result is a weakened pressure gradient, suppressed cyclogenesis over the Bay of Bengal, and a monsoon stripped of its suction power. Pakistan consequently can face reduced overall rainfall, a heightened risk of heatwaves, and the prospect of severe drought.
The Paradox of Drought and Flash Floods
However, the interaction of El Niño with accelerating climate change introduces a dangerous caveat: while total precipitation declines, short bursts of extreme rainfall become more likely, driven by elevated greenhouse gas concentrations and the additional moisture held in a warming atmosphere. The paradox, then, is one of drought punctuated occasionally by flash flooding.
Compounding Water Crisis and Infrastructure Gaps
This confluence of climatic pressures arrives at a deeply precarious moment for Pakistan. India's unilateral suspension of the Indus Waters Treaty threatens to further restrict downstream river flows, directly imperilling the riparian communities and agricultural lands that depend on the Indus system. Compounding this, Pakistan's water storage infrastructure remains critically underdeveloped. The country's two principal reservoirs, Tarbela and Mangla, serve primarily as hydroelectric facilities, and diminished inflows would deplete both power generation capacity and water reserves simultaneously.
Glacial Retreat and Urban Vulnerabilities
Meanwhile, glacial retreat across the Indus basin has accelerated sharply, with perennial ice cover declining by up to 25% between 2001 and 2021. The meltwater floods that periodically inundate parts of the country represent a vast, unharnessed resource, one that could, with adequate storage infrastructure, be preserved for precisely the dry spells that El Niño years bring. Urbanisation adds yet another layer of vulnerability: the neglect of green spaces intensifies the urban heat island effect, while drainage systems choked with waste turn even moderate downpours into public health crises.
A Call for Urgent Action
Pakistan's exposure to climate-related shocks is not the product of any single variable but rather the cumulative outcome of geographic vulnerability, institutional gaps, and decades of deferred adaptation. El Niño does not create Pakistan's climate crisis. It amplifies one already well underway. Meeting this moment demands urgent investment in water storage and management, the restoration of urban green infrastructure, and a concerted diplomatic effort to safeguard transboundary water rights. Without these measures, each successive climate event will extract a heavier toll from a population that has contributed least to the global emissions driving these extremes.
