The future of global Ramsar wetlands under intensifying precipitation extremes: Arid regions as emerging hotspots

Abstract

Wetlands are critical ecosystems sustaining ecological balance, climate regulation, water purification, and biodiversity, yet climate-induced precipitation extremes pose growing threats to their hydrological stability worldwide. This study investigates hydroclimatic regime shifts across 2490 Ramsar wetlands using a climate-informed framework integrating precipitation variability and extremes, assessed through a multi-model ensemble of 13 CMIP6 models for historical (1951–2024) and SSP585 future (2025–2100) periods. In arid regions, annual precipitation increased 9.3 % (337.3 to 368.7 mm) while Ramsar wetlands expanded 14.5 % (447 to 512 sites), reflecting spatial growth under evolving hydroclimatic regimes. Despite remaining driest, arid wetlands exhibit heightened hydrological stress with RR95 frequency rising 16.36 %, R95pTOT contributions increasing 7.74 % (11.21 % to 12.08 %), SDII rising 9.5 % (2.1 to 2.3 mm/day), and Rx1 climbing 11.9 % (12.6 to 14.1 mm), indicating greater event-scale intensity. Across all climate zones, wetland-year records exceeding extreme rainfall thresholds increased significantly, reaching 95 % for R95pTOT in temperate zones and over 80 % in arid regions, demonstrating a global shift toward clustered, intense precipitation events. The expansion of arid zone wetlands coupled with increasing extremes creates a paradoxical risk where short, intense water bursts undermine ecosystem resilience, intensify flash flooding, and disrupt fragile wetland hydrology. These findings underscore urgent needs for climate-resilient wetland management policies tailored to arid and vulnerable regions, with targeted adaptation strategies including early warning systems, sustainable land use, and nature-based solutions essential for preserving wetland integrity aligned with SDG 13 (Climate Action) and SDG 14 (Life Below Water). © 2025 Elsevier Inc.