UN Report: Ageing Populations Face Deadly Climate Threats

As extreme heat grips many countries and becomes “the new normal,” the UN Environment Programme (UNEP) has warned of heightened health risks for older persons in its Frontiers 2025 Report, published today. Other climate change impacts highlighted include melting glaciers that could reawaken ancient pathogens and floods that risk releasing dangerous chemicals.

The 7th edition of the Frontiers Report https://www.unep.org/resources/frontiers-2025-weight-time , titled The Weight of Time – Facing a New Age of Challenges for People and Ecosystems, is part of UNEP’s Foresight Trajectory initiative. It highlights emerging environmental issues and potential solutions. The first edition in 2016 warned of the growing risk of zoonotic diseases, four years before the COVID-19 pandemic. This year’s report comes as communities across China, Japan, India, Europe, the USA, and other regions face weeks of extreme heat and flooding.

“Heatwaves are among the most frequent and deadly impacts of climate change, along with floods and shrinking ice cover,” said Inger Andersen, Executive Director of UNEP. “We must be prepared for the risks these impacts pose, especially for society’s most vulnerable, including older persons. Yet, as this year’s Frontiers Report shows, solutions exist that can help protect communities and restore ecosystems long thought to have been lost.”

Adults aged 65 and above now form an increasingly large part of the global population, particularly in urban areas of low- and middle-income countries. The report notes that annual heat-related deaths among older persons have risen by an estimated 85% since the 1990s. Additional risks stem from deteriorating air quality and floods in low-lying coastal cities where many older persons reside.

Older individuals, especially those with chronic illnesses, limited mobility, or frailty, are particularly vulnerable to heat-related health issues, including respiratory, cardiovascular, and metabolic diseases, as well as increased mortality.

The report recommends making cities pollution-free, resilient, and accessible, with expansive vegetation. Key strategies include better urban planning, community-based disaster risk management, and improved access to climate information for older populations.

Earlier this year, the UN Human Rights Council adopted a resolution to develop an “international legally binding instrument on the human rights of older persons”, a possible path to better protect those most exposed to climate change.

Zombie Microbes

Beyond risks to older persons, the report also warns of ancient microbes awakening. Should global temperatures rise more than 2˚C above pre-industrial levels, it would significantly reduce the cryosphere, which includes glaciers, seasonal snow, ice sheets and shelves, sea ice, seasonally frozen ground, and permafrost. These regions are home to 670 million people and supply water to billions more.

Dormant fungi, bacteria, and viruses in these frozen regions could reactivate, raising the risk of antimicrobial resistance. To slow cryosphere decline, the report recommends cutting greenhouse gas emissions, including black carbon from diesel engines, open-field agricultural burning, and wildfires, and limiting tourism in fragile frozen regions. It also urges accelerated research into cryospheric microorganisms that may not survive the decline.

The Return of Banned Chemicals Through Floods

The report also identifies risks from the remobilization of chemicals banned decades ago. Floods can bring such chemicals to the surface after centuries of sediment accumulation.

As floodwaters stir sediment and debris, toxic chemicals may re-enter urban areas or food systems. The report lists several effective risk-reduction measures: traditional controls like polders, dikes, and retention basins; improved drainage systems; nature-based solutions (e.g., sponge-city approaches); regular monitoring of pollutants; and economic impact studies.

The Risk of Ageing Dams

Another emerging threat addressed in the Frontiers 2025 Report is the risk posed by ageing dams. While dams offer benefits, they can harm indigenous and fishing-dependent communities and degrade ecosystems. The removal of large, older dams, deemed unsafe, obsolete, or economically unviable, is increasingly occurring in Europe and North America.

The report outlines the potential benefits of dam and barrier removal in restoring natural river connectivity and biodiversity. Reversing river fragmentation and restoring natural processes aligns with the UN’s principles for ecosystem restoration initiatives.