fire-damaged street sign marks Main Street in a decimated downtown Greenville, California during the Dixie fire on August 5, 2021. (Josh Edelson/AFP via Getty Images)

The climate crisis is not just about rising seas or shrinking ice caps, it cuts to the heart of how societies hold together and how global order is sustained (Josh Edelson/AFP via Getty Images)

History’s warning: Climate chaos can expose the fragility of world order

Past empires fell when environmental stress met political weakness – today’s global warming poses an unprecedented test of resilience.

Terrence Mullan

24 September 20254 min read

The world feels like it’s spinning out of control. Wars are breaking out, neighbours are turning on each other, people are starving, epidemics are spreading, debt is piling up, and the climate is growing harsher. The rules and norms that once kept some sense of order are falling apart.

But these aren’t headlines from today. It is how Voltaire and others described the 17th century.

History tells us that we’ve been here before. In fact, the world has seen several waves of global unrest – around the middle of the second millennium BC, in the fourth and fifth centuries, the late 13th and early 14th centuries, and again in the early 19th century. Each time, great powers stumbled, and societies questioned whether the orders holding them together could still be trusted.

The climate connection

What’s striking is how often these crises and order changes overlapped with shifts in climate. During these periods, decades of cooling aligned with more sudden climate shocks, triggered by volcanic eruptions, certain ocean and atmospheric patterns, or even dips in solar activity, often preceded or coincided with upheaval. It wasn’t just the shifts in temperature that caused disruptions, but the climate instability that accompanied it, including severe winds, extreme variations in precipitation, and stronger storms. Crops failed. Famines spread. Populations shrank. Epidemics flourished. Prices spiked. Migration and conflict followed.

Climate instability isn’t the root of the problem, but it often plays the role of a spark hitting dry wood – setting off crises in societies already under strain. When political and social institutions aren’t resilient enough to handle the extra stress, even small climate shocks might be enough to cause collapse, whereas in steadier times it usually takes a much bigger shock. But this isn’t a neat, one-to-one chain of cause and effect. Climate stress works more like an outside force that collides with a society’s own vulnerabilities, creating ripple effects that can quickly spiral out of control.

Solar-powered irrigation is an example of productive uses of energy that supports climate-resilient agriculture. Photo: UNDP Zambia

Solar-powered irrigation in Zambia (UNDP)

Today, we’re dealing with something even more dangerous: not natural cycles of cooling, but rapid, human-driven warming. And history suggests that today’s climate instability –accompanied by many of the same crises that natural climate variability brought in the past – can tip the balance during already fragile times. While much work has been done on climate instability’s impact on societies, less research has covered how it may influence world orders.

How climate breaks down order

Throughout history, leaders have tried to forge partnerships, manage rivalries, and gain prosperity. The way they’ve usually done this is by creating world orders – frameworks of governing arrangements that guide how nations deal with one another. At their core, these orders set the rules of the game. Over time, they give rise to shared institutions including diplomacy, trade, international law, and even the rules of war, which shape how countries should behave.

World orders depend on real systems of power and trust. Each instance where order was established and sustained, a great power or powers held them together in two ways. First, by enforcing rules when necessary, through military or economic strength. And second, by persuading others that those rules are legitimate.

With smart choices and a willingness to adapt, societies and orders can come out stronger.

Climate instability can erode both pillars of order. Since an order’s functioning depends heavily on its most powerful members, destabilisation of those powers places the entire order under severe strain. On the micro level, people lose confidence in institutions, living standards drop, and the sense grows that old systems no longer work. On the macro level, those leading powers suddenly have fewer resources: tax bases shrink, inflation rises, and armies and workforces dwindle. In that kind of environment, holding a global order together becomes almost impossible. A great power that is overextended, financially unstable, and facing a determined rival isn’t just weakened – it’s on a fast track to losing the order it constructed.

Lessons ignored

Historians have shown again and again how climate can influence the fate of empires and civilizations – from Rome and Angkor to the Maya. However, we also know of times when societies proved surprisingly resilient – even in the chilly period known as the Little Ice Age. Take the Tokugawa shogunate in Japan: it faced serious climate pressures but responded by centralising power, scaling back the military, cutting taxes, and building strong transport and communication networks. The Dutch thrived by leaning into trade and commerce while setting up widespread local welfare programs. These stories remind us that climate stress doesn’t always spell disaster. With smart choices and a willingness to adapt, societies and orders can come out stronger.

In the past, even a single degree of warming was enough to unleash famine, epidemics, and chaos. Now we’re staring down a rise of 2.5°C or more. The dangers are on a whole different scale – and yet many countries are sleepwalking into crisis. For the United States, the stakes are even higher: climate stress doesn’t just threaten social and political stability at home, it could also bring the US-led order to an end.

The climate crisis is not just about rising seas or shrinking ice caps, it cuts to the heart of how societies hold together and how global order is sustained. History shows that when the environment turns unstable, institutions can falter, resources can dry up, and even the most powerful states can stumble.

The real question isn’t whether climate change will test today’s world order – it’s whether we’re willing to adapt before that test becomes a breaking point.

About the author

Terrence Mullan

Terrence Mullan is a PhD candidate in the Department of International Relations at the London School of Economics and Political Science, where his research focuses on how historic periods of climate instability impacted international order change.

Topics

Climate & environment