António Guterres issued the warning in a video message to the inaugural Sagarmatha Sambaad, or “Everest Dialogue,” convened by the Government of Nepal in Kathmandu.

“Record temperatures have meant record glacier melt,” he said.

“Nepal today is on thin ice – losing close to one-third of its ice in just over thirty years. And your glaciers have melted 65 per cent faster in the last decade than in the one before.”

Named after Mount Everest (Sagarmatha in Nepali), the international platform convened ministers, parliamentarians, climate experts, and civil society to focus on climate change, mountain ecosystems, and sustainability.

Two billion futures at stake

Glaciers in the region have served for centuries as vital freshwater reservoirs. Their accelerated melt now threatens not only local communities but vast populations downstream who rely on Himalayan-fed rivers.

Reduced water flow in river systems such as the Ganges, Brahmaputra and Indus threatens not only water but also food production for nearly two billion people across South Asia.

Combined with saltwater intrusion, this could trigger collapsing deltas and mass displacement, the UN chief warned.

“We would see low-lying countries and communities erased forever,” he said.

Children raise their voices

Ahead of the summit, Nepal’s children and youth stepped into the spotlight with their own call to action.

In a declaration submitted to the dialogue, over 100 children and young people demanded urgent and inclusive climate action that recognizes them as rights-holders and climate actors – not just passive victims.

Among their key demands: ensuring child participation in climate decisions, supporting youth-led programmes, and promoting their innovations and climate action.

“The climate crisis is a child rights crisis – disproportionately impacting their health, nutrition, education and well-being,” said Alice Akunga, head of the UN Children’s Fund (UNICEF) in Nepal, which supported the deliberations.

“Listening to the voices of the ‘future of humanity’ is critical to designing and implementing meaningful and lasting solutions to address the adverse effects of climate change on children and youth.”

Stop the madness

In his message, Mr. Guterres reiterated his call on the world to “stop the madness” of fossil fuel-driven global warming, a warning he made during his previous visit to the Everest region in 2023.

At the time, he stood amid glacial basins in the Himalayas, warning that the “rooftops of the world” were rapidly vanishing.

“And that is why you are gathered together focused on Sambaad – dialogue,” the UN chief said on Friday, applauding Nepal’s climate leadership, including reforestation programmes, early warning systems and its goal to achieve net-zero emissions by 2045.

Act now

The world must act without delay to limit global temperature rise to 1.5°C, he continued – the target set by the Paris Agreement on climate change – with the biggest emitters leading the way.

This includes investing in renewable energy, fulfilling the $1.3 trillion climate finance goal agreed at COP29, doubling adaptation finance to at least $40 billion this year as pledged by developed countries, and providing robust, sustained support to the Loss and Damage Fund.

“Achieving these goals demands bold collaboration,” Mr. Guterres concluded. “The United Nations is your ally in this essential task.”