The United Nations Environment Programme (UNEP) released its 7th Frontiers report, *The Weight of Time*, in July 2025. It warns of growing threats from extreme heat and toxic pollution to the world’s ageing population. The report marks how climate change and environmental hazards increasingly endanger older adults, especially in urban and low- to middle-income regions.
Rising Heat Threats to Older Adults
Heat-related deaths among people aged 65 and above have surged by 85% since the 1990s. If global temperatures rise by 2°C, deaths could increase by 370% by 2050. Older adults have reduced ability to regulate body temperature. Extreme heat raises risks of cardiovascular, respiratory, and cerebrovascular diseases such as stroke and pneumonia. Tropical and mid-latitude regions face doubled or even tenfold rises in dangerous heat exposure. India already shows increased heatwave days for the elderly.
Urban Ageing and Climate Vulnerability
Cities will house 68% of the global population by 2050, with a rising share of older residents. In 2015, 58% of people aged 60+ lived in urban areas. Older people often move to cities for healthcare and social access. However, urban heat islands and pollution worsen risks during heatwaves and climate disasters. The report urges cities to become age-friendly, resilient, and greener to protect elderly residents.
Legacy Pollutants and Flood Risks
Flooding can release toxic legacy pollutants buried in sediments. These include heavy metals like lead and cadmium, and persistent organic chemicals from pesticides and industrial waste. Such pollutants do not degrade easily and accumulate in rivers, lakes, and coastal sediments. Floodwaters can spread these toxins into the environment and food chains, causing neurotoxicity, cancer, and reproductive harm. Examples include floods in Texas (2017), Niger Delta (2012), and Pakistan (2010, 2022).
Environmental and Health Impacts of Pollutants
Cadmium and other pollutants harm sediment-dwelling organisms and humans. Cadmium is carcinogenic and disrupts endocrine functions. It can damage kidneys, bones, and affect pregnancies. UNEP calls for more research on pollutant release during floods to assess risks to ecosystems and health. Monitoring polluted sediments is crucial as rainfall intensity and flood events increase globally.
Solutions – Urban Planning and Flood Management
The report recommends the ‘15-minute city’ model to support ageing in place by ensuring essential services are within walking or cycling distance. This reduces car use and pollution. Flood-control strategies should combine nature-based solutions like wetlands restoration with traditional infrastructure such as dikes and retention basins. River basin management plans must balance flood retention with ecosystem conservation. Adaptive management and community involvement are vital for effective response to contaminant remobilisation.
