Film depicts Earth after extinction of humanity
By Jasper Hamill

It's the end of our world and feral domestic pets stalk the deserted cities of Scotland. Holyrood lies in ruins and the Clyde has burst its banks.

This vision is the basis for the History Channel's Life After People, which depicts the collapse of major cities if humanity were to suddenly disappear.

Director Douglas Cohen described it as a "reflection on our mortality", achieved by imagining a world where a virus or other event had killed off mankind. He said: "While this film deals with a hypothetical scenario, it's very much a documentary and a creative way of examining both the impact of humans on the planet and the fragility of everything we have created.

"The speed with which nature reclaims neglected human structures is astounding. Once you see this film, you will never look at those weeds you pull from the garden in quite the same way."

The fates of London, Rome, New York and Paris have been simulated before but Scotland's cities have largely been left off camera.

Gordon Masterton, a civil engineer from Glasgow, advised on how buildings might fare without humans to maintain them. In Scotland, it would be the older buildings that would last the longest.

"Everything we build has the seeds of its own destruction," he said, "so without human intervention they would simply rot away. The trouble with modern buildings is that we design them to be efficient. When we were building with masonry blocks they were made stronger than they needed to be. So all the old arched bridges, like the Victorian ones across the Clyde, would survive for centuries, while structures such as the Erskine bridge would collapse."

Glasgow's City Chambers and the National Museum of Scotland in Edinburgh, built of sandstone, would last hundreds of years, after losing their timber-framed roofs to rot and woodworm. While Edinburgh Castle survived and became overgrown, modern buildings such as Holyrood, made from steel, glass and concrete, would collapse relatively quickly.

Without upkeep, Glasgow's tenements would concertina after a few years of storms and subsidence, while the subway would fill with mud and towerblocks topple in on themselves. Edinburgh, more sturdily built, would last longer, and still be recognisable for up to three centuries. The Forth bridge might survive for several centuries, until it eventually corroded into a pile of rusted metal to drop piece by piece into the river.

While cities would rot, wildlife would flourish, but the damage wrought by mankind would prevent ecosystems returning to their pre-industrial state, when the flora and fauna was closer to that of mainland Europe and bears and wolves roamed the land.

Roger Downie, professor of zoological education at Glasgow University, said that humans have broken natural control systems. "What would happen to wildlife is slightly unpredictable because of the way we have manipulated what the environment is like, particularly in terms of deforestation and the loss of predators such as wolves," he said.

This lack of large carnivores would lead to a population explosion of wild sheep, deer and cattle. Unharried by predators, they would eat so much foliage that there would be little chance of the ancient Caledonian forest regrowing. Unless a wolf were to journey through the Channel Tunnel, the only meat-eaters would be eagles or feral dogs and cats, which would eventually evolve into wild predators.

The heather and gorse of the Highlands would be choked by rhododendron, which was first introduced to Scotland by gardeners in the 19th century and is fast-growing and well suited to mountain climates.

The point of the film, to be broadcast next weekend, is to stimulate discussion of the environment without a preachy, doom-laden tone, said Alan Weisman, who wrote the book that first imagined Earth free of mankind: The World Without Us.

"The future is seductive. People always want to know what will happen and I thought this would be a good way of removing the fear factor from reading environmental stuff," said Weisman.

Life Without People airs on The History Channel, Sunday March 23, 9pm