Collapsing Glaciers, Climate Change and Human Security

For the people of Nepal, climate change isn't just an environmental issue. When a glacier collapses, it's a question of who lives, who dies, who has water, who has a home and whether an entire community remains habitable. That's human security.

This week’s catastrophic flooding in Nepal is an appalling illustration of what that means. A huge mass of ice, rock and debris collapsed high in the Himalayas, generating a devastating surge through valleys and settlements below. Hundreds are already confirmed dead and many more remain missing, while villages, roads, bridges, electricity infrastructure and livelihoods have been destroyed. The final toll is not yet known.

Scientists will rightly be cautious about attributing any single glacier collapse directly to climate change. But there's no serious doubt about the broader trend. The Himalayas are warming, glaciers are retreating, permafrost is thawing and mountain slopes are becoming less stable. Across the Hindu Kush Himalaya, the rate of glacier loss has doubled since 2000, while the World Meteorological Organization reported that every one of the High Mountain Asian glaciers it monitored lost mass during 2025.

This matters because glaciers aren't just spectacular scenery. They're part of the life-support system for much of Asia. They store water, feed major rivers, sustain agriculture, generate electricity and support communities and economies across national borders. Nearly two billion people depend to some extent on water originating in the Hindu Kush Himalaya.

Climate change creates a cruel paradox for these communities. In the short term, rapid melting can mean too much water as glaciers retreat, glacial lakes grow and unstable slopes collapse. Over the longer term, shrinking glaciers mean less reliable water flowing into rivers during dry periods. The same process can thus increase flood risks and future water scarcity.

This is an example of why climate change is fundamentally a human security issue. We still tend to think of security in terms of borders, armies, weapons and alliances. But human security asks a more basic question: are people actually safe? Do they have secure access to water, food, housing, energy, health care and livelihoods? Can communities withstand disasters without being destroyed or displaced?

A report released by the United Nations Development Programme only months before this disaster warned climate change in the Himalayas was already threatening water, food, energy, livelihoods and communities across the region. Environmental disruption doesn't remain neatly confined to the environment. It cascades through societies and economies.

That's what people mean when they describe climate change as a threat multiplier. It can destroy a bridge and isolate communities, wipe out crops and increase food insecurity, damage power generation, force people from their homes and intensify pressure on governments already struggling with poverty or inequality. In river systems shared by several countries, climate impacts can also become questions of diplomacy and regional security.

The response therefore has to involve both mitigation and adaptation. We need to reduce greenhouse gas emissions because every additional increment of warming increases these risks. At the same time, vulnerable countries need much stronger glacier monitoring, early-warning systems, evacuation planning, resilient infrastructure and cross-border cooperation.

There's a lesson here for Australia too. Our own governments increasingly recognise climate change as a national security risk, yet our political debate still too often treats security spending and climate spending as belonging to completely different worlds. They don't. Protecting people means more than defending borders. It means protecting the environmental and social systems that allow people to live safely in the first place. A stable climate, secure food and water supplies, functioning ecosystems, resilient infrastructure and strong communities are all part of national security.

For the people living beneath the Himalayas, that distinction is already painfully clear. Climate change isn't an abstract line on a graph or a problem for some distant future. Sometimes it's a flood. Sometimes it's the destruction of a village. And sometimes, quite literally, it's the mountain coming down.

That's not merely an environmental crisis. That's human security.

Photo: The Star.