The rising frequency and intensity of extreme heat events are now a defining feature of the global climate crisis, with profound effects on the ecological resilience and environmental sustainability of ecosystems. Here, the cascading impacts of rising temperatures on terrestrial and freshwater ecosystems are critically discussed, with a focus on novel emerging vulnerabilities in climate-affected regions. The nations of the Arab world, such as Iraq and Kuwait, have experienced record-high temperatures exceeding 50 °C in recent decades, resulting in extreme droughts, agricultural disruption, water shortages, and infrastructure collapse. Based on peer-reviewed literature syntheses and local climate data, the review identifies four principal ecological effects: reduced vegetation productivity and soil water storage, increased wildfire frequency, freshwater ecosystem stress, and marine ecosystem decline. Ocean warming has exacerbated coral bleaching, altered species migration, and reduced dissolved oxygen, threatening biodiversity and coastal livelihoods. These occur most vehemently in locations with low adaptive capacity, particularly in the Global South. Severe heat also accelerates the release of greenhouse gases through thawing permafrost and damaged carbon sinks, trapping dangerous climate feedback loops. Compared to other analyses of land or ocean systems in isolation, this review includes cross-ecosystem impacts to provide an end-to-end overview of thermal stress.
To mitigate the risks posed by these threats, the study calls for urgent, science-informed adaptation measures, including climate-resilient agriculture, nature-based cooling, early warning systems, and interregional environmental cooperation. Special emphasis is put on hyper-arid regions in the Middle East, which are likely to experience more intense heatwaves in the coming decades.
This study contributes to the understanding of how extreme heat affects the environment. It highlights the need for equitable and practical solutions to protect both nature and communities as the planet continues to warm.