Geneva: Deadly floods across the globe this month have resulted in hundreds of casualties and have exposed critical shortcomings in early warning systems, the United Nations' weather agency has reported. The devastation has been linked to rapid urbanization, changes in land use, and a warming climate that traps more moisture in the atmosphere.

According to United Nations, the World Meteorological Organization (WMO) announced that intense downpours and glacier outburst floods are becoming more frequent, leading to fatal consequences for unprepared communities. Stefan Uhlenbrook, WMO Director of Hydrology, Water, and Cryosphere, indicated that flash floods, though not a new phenomenon, are increasing in frequency and intensity due to urban expansion, land-use changes, and climate change.

Floods and flash floods claim thousands of lives annually and cause billions in damages. In 2020, severe flooding in South Asia resulted in over 6,500 deaths and $105 billion in economic losses. Two years later, catastrophic floods in Pakistan left more than 1,700 dead, affected 33 million people, and incurred losses exceeding $40 billion, negating years of developmental progress.

This year, the trend has persisted. July alone saw South Asia, East Asia, and the United States facing deadly events, from monsoon rains to glacial lake bursts and sudden flash floods. In India and Pakistan, heavy monsoon rains have disrupted transport, destroyed homes, and triggered landslides. Pakistan declared a state of emergency in its most affected areas, employing military helicopters for rescues following forecasts of exceptional flood risks along the upper Jhelum River.

The Republic of Korea experienced record-breaking rainfalls from July 16-20, with some areas receiving over 115 mm per hour, resulting in at least 18 deaths and the evacuation of more than 13,000 people. In southern China, flash flood and landslide alerts were issued on July 21, following Typhoon Wipha's impact on Hong Kong, highlighting the compounded risks from sequential storms.

In the United States, a sudden overnight deluge on July 3-4 turned Texas Hill Country into a disaster zone, killing over 100 people and leaving dozens missing. The Guadalupe River basin was overwhelmed with 10-18 inches of rain, causing the river to surge 26 feet in just 45 minutes. Despite the US National Weather Service issuing warnings beforehand, local sirens were inadequate, and final alerts were given when most were asleep.

Not all floods were rain-induced this month. In Nepal’s Rasuwa district, a sudden outburst from a supraglacial lake on July 7 swept away hydropower plants, a major bridge, and trade routes, killing at least 11 people and leaving more than a dozen missing. According to scientists at the International Centre for Integrated Mountain Development (ICIMOD), a WMO partner, glacier-origin floods in the Hindu Kush-Himalaya region are occurring far more frequently than two decades ago. The risk could triple by the end of the century if warming trends continue.

To address these challenges, the WMO is enhancing flood forecasting through its global initiative and real-time guidance platform, which is currently used in over 70 countries. The system, which integrates satellite data, radar, and high-resolution weather models, aims to provide advance warnings and is being expanded into a globally interoperable framework led by individual countries. A 2022 World Bank study estimated that 1.81 billion people, nearly a quarter of the global population, are directly exposed to 1-in-100-year flood events, with 89 percent residing in low- and middle-income countries.