The Fens, a vast and fertile region in eastern England, span parts of Cambridgeshire, Lincolnshire, and Norfolk. This area is crucial for food production, supplying about a third of the UK’s vegetables and supporting tens of thousands of jobs. However, much of the Fens lies below sea level, with 33% of the region sitting below average sea level and 87% below the highest spring tides. This unique landscape has been shaped by centuries of human engineering, including pumping stations, embankments, and drainage systems that continuously remove water to keep the area habitable and productive. Climate change is now presenting new and complex challenges to the Fens’ infrastructure, which was not designed to handle the extreme conditions of the future. The region is facing multiple interconnected threats, including rising sea levels, more intense rainfall, hotter summers, longer droughts, and the loss of biodiversity. These issues are expected to worsen over the coming decades, putting both the environment and local communities at risk. A recent academic study published in June highlights the potential impacts of climate change on the Fens. With a global temperature increase of 2°C, the region could experience more frequent flooding, extreme heat, reduced river flows in the summer, and faster loss of biodiversity. In a more severe scenario with 4°C of warming by 2100, annual flood damage to homes and businesses could increase dramatically—from £16 million to £250 million. Ecosystems may also collapse, and some parts of the Fens could become uninhabitable without major investments in infrastructure. Sea-level rise, in particular, is a long-term threat that will continue to pose risks for centuries, even if global warming is stabilized. The Environment Agency’s Fens 2100+ program, published in April 2026, echoes these concerns. It emphasizes the need for a coordinated approach to managing flood risks, involving the maintenance and upgrading of around 17,000 assets, such as 318 pumping stations, embankments, and tidal defenses. These efforts are projected to prevent £58.8 billion in flood damage over the next century. However, nearly a third of the current defenses require upgrades within the next 15 years to remain effective. Both the academic analysis and the Fens 2100+ program stress that addressing these challenges in isolation or only in the short term is not enough. The Fens must be treated as a connected landscape, with decisions on flood protection, water management, agriculture, and the environment made together. Similar challenges are faced by other coastal lowlands worldwide, such as the Netherlands and the Mekong Delta in Vietnam. The strategies developed for the Fens could serve as a model for helping other regions assess and adapt to their own climate risks.