GAR 2025 Hazards: Storms
In some regions, storms account for up to 35% of total recorded disaster costs, driven by high winds, storm surges, and heavy rainfall.
Between 1970 and 2019, water-related hazards accounted for 50% of all disasters and 45% of all reported deaths. Floods and storms are responsible for a range of often unaccounted indirect impacts to people and planet, destroying ecosystems and driving disaster-related displacement. The number of people exposed to floods globally has also steadily risen from 28.1 million in 1970 to 35.1 million in 2020—an increase of 24.9%. Most flood-related deaths and economic losses are recorded in Asia.
Probabilistic approaches can also help understanding flood risk over time, beyond the specific fluctuations that may occur from year to year. By providing a consistent metric to measure and compare potential damages annually, it can help guide decisions about flood protection and land use, particularly in the content of climate change and rapid urbanization. Average annual losses from tropical cyclones alone are estimated at USD 119.5 billion, including USD 95.5 billion in infrastructure.
South Korea and Japan, which already endure notable impacts nowadays, are projected to experience substantial increases in the proportion of their populations affected under future conditions, unless resilient investment is stepped up.
Annual Average Economic Losses in USD by Floods and Cyclones for the Education Sector
Source: UNDRR based on CDRI datasets (downloaded 28 March 2025)
More than half (USD 165.8 billion) of the total USD 295.5 billion in disaster-related AAL (including landslides and tsunamis) within the critical infrastructure sectors are attributable to floods and cyclones. Cyclones are responsible for USD 91.7 billion (55%) of these losses, with the remainder (USD 74.1 billion) attributed to floods. Compared within regions, AAL for critical Infrastructure sectors due to floods and cyclones is 68% for Oceania, 40% for Europe, 53% for Asia, 65% for Africa and 68% for the Americas.
The IPCC makes clear that the severity of storms such as tropical cyclones will increase with warmer sea temperatures. Tropical cyclones are also expected to move poleward, given that new regions will likely see their oceanic temperatures reach 26°C (the minimum threshold for cyclones to occur). This means that areas not previously susceptible will need to learn how to prepare.
Future Storms risk
The economic impacts of storms – already immense – are expected to worsen in the future. Currently, the losses generated by tropical cyclones contribute to storm surges, precipitation, flooding and winds that together generate average annual losses of USD 112 billion. In the current climate, a 1-in-100-year tropical cyclone would affect between 65 and 80 million people. By 2050, in a high-emission climate change scenario (RCP8.5), these losses could increase by 35.6% to USD 152 billion annually.
In absolute values, the main countries affected would be the United States of America, Japan and China. However, in relative terms, low-income countries such as small island developing states (SIDS) – may suffer far greater impacts and have fewer resources to prevent disasters and to support their recovery.
The impacts of increased storms also undermine fragile ecosystems like mangroves and coral reefs. For example, at present, 97% of the risk of substantial damage to mangroves is due to storms that develop into major (category 3–5) tropical cyclones. These destroy natural buffers such as mangroves and protect people and their assets from storm surge and the full force of winds and floods.
GAR 2025 Hazard explorations
For the big five major hazard groups (earthquakes, floods, storms, drought and heat) the recorded direct economic costs came to over USD 195.7 billion in 2023, constituting 0.015% of global GDP that year.
Earthquakes account for over a quarter (25.6%) of global economic disaster losses.
Recent data suggests that floods account for up to 35–40% of weather-related disaster occurrences.
In some regions, storms account for up to 35% of total recorded disaster costs, driven by high winds, storm surges, and heavy rainfall.
Droughts often unfold slowly, but with far-reaching impacts on agriculture, water supplies, and economic stability.
In recent years, extreme heat has become the leading cause of reported weather-related deaths
.
