By Michael Leadbetter

If you, like the majority of the world’s population, live in a city, you are particularly vulnerable to climate change.

The 21st Century is not the first time humans have faced climate change and the challenges it poses. The archaeological record is filled with examples of how past societies and cultures that have survived climate change, as well as those that did not. But, while there is much talk of futuristic sci-fi solutions to climate change, there is no talk of the past.

Much like the abandoned cities of Angkor, Anuradhapura in Sri Lanka and Tikal in Guatemala, our cities are becoming huge sprawling entities, eating up the surrounding landscape.

Climate played a key role in the political and population collapse of many of the largest cities of the preindustrial world: cities such as Angkor in Cambodia, Anuradhapura in Sri Lanka, and Tikal, the great city of the Mayan lowlands in modern Guatemala.

Large cities are often resilient to sporadic climate disruption such as extreme weather. Research by archaeologists at the University of Sydney has found that ancient Angkor survived several climate shifts. After irregular monsoons, thousands of kilometers of canals and water tanks – equivalent in size of medieval London – were built to protect the mega-city’s water and food supply. While costly, the huge infrastructure enabled Angkor to grow into the most extensive urban city of the preindustrial world, 60 kilometers across, a similar size to greater Sydney or Melbourne.

However, when faced with major and intense climate change, large cities are far less resilient.

In ancient cities such as Angkor, there was a cost benefit trade off to make the city habitable. The tipping point came when the cost of repairing or maintaining the city and its infrastructure outstripped the society’s capacity or desire to pay for its upkeep. The consequence was the failure of the agricultural system that, along with trade, had sustained a population of over a million people.

In Angkor, the disastrous sequence of events was years of drought followed by a catastrophic monsoon. The drought left huge water tanks and canals in bad repair. Unable to cope with the deluge, they became filled with debris and silt. The fields that supplied the city with rice – its source of nutrition and also its key trade product – were rendered useless and the city was almost completely abandoned.

Two factors make collapses such as that which occurred in Angkor particularly disturbing. First, the collapse was sudden and rapid, with abandonment, or at least population decline, of cities taking place within a few years. Second, when large, sprawling, resource-hungry cities collapse, they take their entire economic and political system with them, despite the society’s implementation of "tech fixes," like water infrastructure.


Photo Credit:AP/ 達志影像

Tourists check out the stunning view of the Angkor Wat temples outside Siem Reap, Cambodia.

Why should we be worried? Well, much like the abandoned cities of Angkor, Anuradhapura in Sri Lanka and Tikal in Guatemala, our cities are becoming huge sprawling entities, eating up the surrounding landscape. Like cities of the past, modern urban centers such as Jakarta, Bangkok, Sydney, Shanghai and London are increasingly interconnected, dependent on the life blood of international trade to generate wealth and continual growth whilst also meeting the ever-growing costs of mitigating climate change. These factors make us vulnerable in the same way as the ancient cities of the past were.

Pressure on infrastructure and liveable space from growing populations, decreased food security and trade activity due to erratic weather patterns, and inundation of coastal cities by rising sea levels or damaged by natural disasters could, in a worst-case scenario, result in similar outcomes: abandonment.

Read next: INFOGRAPHIC: How Climate Change Will Impact Taiwan

This article was first published at New Mandala – a specialist website on Southeast Asian affairs based at the Australian National University’s Coral Bell School of Asia Pacific Affairs.

The News Lens has been authorized to republish this article. The original can be found here.

TNL Editor: Morley J Weston