The UNEP Frontiers 2025 report, “The Weight of Time – Facing a new age of challenges for people and ecosystems”, warns that climate change and environmental degradation are driving emerging risks that may seem minor today but have global consequences. It identifies four critical issues: the thawing cryosphere that could release ancient microorganisms; the growing movement to remove aging dams to restore river health; the demographic shift of an aging global population increasingly vulnerable to climate hazards; and the remobilization of legacy pollutants during severe floods.
Thawing ice and ancient microbes: a frozen pandora’s box
The thawing of glaciers and permafrost due to rising global temperatures is unlocking a “frozen Pandora’s box” of microbes that have been dormant for millennia. This carries both risks and opportunities. On the one hand, reactivated fungi, bacteria, and viruses could release pathogens and antimicrobial resistance genes into ecosystems and human populations unprepared to face them. A stark example occurred in Siberia in 2016, when thawed permafrost released Bacillus anthracis spores, causing an anthrax outbreak that killed thousands of reindeer and sickened people. On the other hand, not all microbes are dangerous; some may hold immense value for biotechnology, medicine, and climate research. The UNEP Frontiers 2025 report stresses the urgency of preserving and studying this microbial diversity through measures such as biobanks, as these organisms may yield breakthroughs before disappearing with the ice. Ultimately, the thawing cryosphere is a warning of global change, underscoring the need for stronger disease surveillance and intensified climate mitigation efforts worldwide.
Restoring rivers by removing obsolete barriers
Dams have long been pillars of development, taming rivers for hydropower, irrigation, and flood control. However, these benefits have come at an ecological cost. Dams and weirs fragment waterways, disrupting natural flow regimes, blocking fish migrations, trapping sediment, and altering riverine habitats. Communities downstream may lose fertile silt deposits, while upstream reservoirs inundate land and displace people. Over time, many dams also age and become safety or economic liabilities. The Frontiers 2025 report notes a growing international trend to address this legacy: removing obsolete or harmful dams to restore river health.
The demographic challenge: growing old in a changing climate
The global population is aging rapidly, with adults over 65 projected to rise from 10% in 2024 to 16% by 2050, especially in low- and middle-income countries. While Uganda remains one of the youngest nations, its elderly population will also expand, from about 3% in 2015 to 4-5% by 2050. This demographic shift means that millions of Ugandans will grow old in a climate marked by rising heat, worsening air pollution, and more frequent floods. Older adults are particularly vulnerable due to reduced physical resilience and chronic health conditions, making extreme heat waves especially deadly. The UNEP Frontiers 2025 report emphasizes the need for age-friendly, climate-resilient development. This includes urban planning that reduces hazard exposure, such as green spaces to cool cities, safe housing and healthcare facilities, improved drainage, and cleaner air. Strengthening social systems is also vital: disaster preparedness must integrate older people’s needs, heatwave alerts should reach caregivers, and emergency transport should be accessible. These measures not only protect seniors but also make communities more resilient for all.
Floods unleashing legacy pollution: forgotten but not gone
Floods are not only destructive to lives and infrastructure but can also remobilize long-buried pollutants such as heavy metals and banned chemicals like DDT, creating what UNEP calls “forgotten but not gone” pollution. Climate change, by intensifying extreme rains and floods, is disturbing contaminated sediments and spreading toxins back into ecosystems and communities, as seen in Pakistan, Nigeria, and the U.S. In Uganda, the Nyamwamba River has repeatedly eroded abandoned mining tailings, washing heavy metals downstream. Addressing this challenge requires proactive mapping and remediation of legacy pollution sites, integrating pollution control into flood management, and adopting nature-based solutions such as wetland buffers and sponge-city designs. Regular monitoring of water, sediment, and food products is vital for early warning, while public awareness and emergency response capacity must be strengthened so communities recognize not just the dangers of floodwaters, but also the toxic substances they may carry.
The UNEP Frontiers 2025 report warns that hidden environmental risks are now surfacing, from ancient microbes released by melting ice, to aging dams, legacy pollutants, and demographic shifts colliding with climate pressures. For Uganda, these global issues carry immediate local relevance. Though the country lacks permafrost, it still faces the downstream effects of emerging pathogens, depends on dams with long-term ecological costs, and must prepare for an aging population in a climate-challenged future. Floods in areas like Kasese already threaten to remobilize toxic pollutants from old industrial sites. The central lesson is foresight and preparedness: Uganda can manage these risks by investing in research, monitoring, and inclusive planning. The country can transform threats into opportunities, protecting public health, restoring ecosystems, and fostering resilience. As UNEP’s Inger Andersen notes, solutions exist to safeguard communities and revive ecosystems once thought lost.
