The climate crisis is forcing some countries to redraw their borders

For millennia, natural features like mountains, rivers, and forests have served as informal boundaries, separating early communities.

As societies evolved, the need for formal borders grew—initially to protect resources but also to define cultural and political identities. Today, the world's 315 land borders are the result of agreements between neighbouring countries, often based on the natural features that separate them.

Yet, borders rooted in nature are increasingly under pressure. As global temperatures rise, glaciers retreat, rivers shift, and forests burn.

Fluid borders

The prospect of redrawing borders due to the climate crisis is a real, though not yet widespread, challenge.

This September, Switzerland and Italy were forced to adjust their border along the Matterhorn due to melting glaciers that reshaped the Alpine watershed. Glaciers across Europe, the world's fastest-warming continent, are retreating, forcing countries to confront the realities of a warming world.

"The shifting of European borders shows that even political boundaries are not immune from the impacts of climate change," Hannah Cloke (OBE) professor of Hydrology at the University of Reading, tells TRT World.

While the changes along the Matterhorn may seem minor, they signal a broader trend: as natural landmarks shift, so too might our concept of territorial boundaries.

But this isn't something new, as borders have been known to shift before.

Benoit Mayer a climate law expert also from the University of Reading tells TRT World, "Look at India and Bangladesh, their border is defined based on tributaries in the land between them, and sometimes the main tributary can move from one place to the other depending on the monsoon.

"The border can actually move by several kilometres. It's dramatic. And that means some lands switch between India and Bangladesh."

Land and sea

Future world maps may look dramatically different due to rising sea levels, which threaten to submerge extensive portions of coastal nations and entire communities.

Projections suggest that without significant reductions in greenhouse gas emissions, sea levels could rise by up to three metres by the early 2100s, potentially displacing over 550 million people and erasing large sections of coastlines.

"Since the signing of the Paris Agreement, our understanding of the risks from loss of cryosphere - especially the great ice sheets of Antarctica and Greenland - has grown, with potentially higher and faster sea-level rise, and at lower temperatures than believed in 2015," Pam Pearson, director at ICCI said in a report last month.

Mayer is all too aware of the challenges to maritime boundaries.

Small island nations like Kiribati and the more popularised case of the Maldives, face the risk of disappearing entirely, which would not only mean the loss of land but also their surrounding Exclusive Economic Zones (EEZs), critical for fishing rights.

"Sea-level rise could see countries lose significant portions of their maritime entitlements," Mayer explains, affecting both local economies and international relations.

Climate migration

The implications of shifting borders extend beyond geography—they influence human lives directly. As the climate crisis alters landscapes, reports suggest it may also force unprecedented levels of migration.

The UNHCR reported that the number of forcibly displaced people exceeded 100 million for the first time in 2022. Climate-related disasters displace around 24 million people each year, from Pakistan's catastrophic floods to droughts in the Sahel. With global warming intensifying, millions more could be forced to move from uninhabitable areas, challenging the conventional borders etched on maps.

Mayer urges caution against alarmism: "Most people migrate short distances, and the majority remain within their own countries." He notes that while the climate crisis exacerbates migration, it is usually part of a complex set of factors, including economic instability.

"People may be forced to migrate after losing their livelihoods due to extreme weather events, but it is often economic challenges that make migration necessary," he said.

Migration, far from being a new phenomenon, has been a fundamental part of human history. In past centuries, people moved with the seasons or sought new resources. Today, structured borders and immigration policies make such movement more difficult.

Yet, as climate pressures mount, the conversation is shifting towards viewing migration not as a crisis but as a necessary adaptation strategy. "If people have no decent chance of staying in their home countries, then of course they should migrate to survive," says Mayer.

Beyond the human impact, the changing climate is reshaping the natural world. Cloke emphasises the broader ecological shifts may matter more so than shifting borders.

"The rapid shift in wet and dry zones in rainforest regions means that crucial habitats are being lost or degraded faster than ever," she warns. For her, these shifts are far more significant than the small adjustments to political borders.

As climate change continues to reshape the planet, our understanding of borders—both physical and conceptual—will need to evolve. From melting glaciers in the Alps to sinking islands in the Pacific, the pressures of a warming world could face us to adapt to our shared spaces on this ever-changing Earth.