The new doomsayers all point to the same collection of threats - climate change, resource depletion and population imbalances being the most important. What makes them especially afraid is that many of these dangers are interrelated, with one tending to exacerbate the others. It is necessary to tackle them all at once if we are to have any chance of avoiding global collapse, they warn.

Many societies - from the Maya in Mexico to the Polynesians of Easter Island - have collapsed in the past, often because of the very same dangers that threaten us. As Diamond explains in his recent book, Collapse, the Maya depleted one of their principal resources - trees - and this triggered a series of problems such as soil erosion, decrease of useable farmland and drought. The growing population that drove this overexploitation was thus faced with a diminishing amount of food, which led to increasing migration and bloody civil war. The collapse of the civilization on Easter Island followed a similar pattern, with deforestation leading to other ecological problems and warfare.

Unlike these dead societies, our civilization is global. On the positive side, globalization means that when one part of the world gets into trouble, it can appeal to the rest of the world for help. Neither the Maya nor the inhabitants of Easter Island had this luxury, because they were in effect isolated civilizations. On the negative side, globalization means that when one part of the world gets into trouble, the trouble can quickly be exported. If modern civilization collapses, it will do so everywhere. Everyone now stands or falls together.

Global collapse would probably still follow the same basic pattern as a local collapse but on a greater scale. With the Maya, the trouble began in one region but engulfed the whole civilization. Today, as climate change makes some areas less hospitable than others, increasing numbers of people will move to the more habitable areas. The increasing population will make them less habitable and lead to further migration in a domino effect. Huge movements of people and capital will put the international financial system under strain and may cause it to give way. In his book The Future of Money, the Belgian economist Bernard Lietaer argues that the global monetary system is already very unstable. Financial crises have certainly grown in scale and frequency over the past decade. The South-east Asian crisis of 1997 dwarfed the Mexican crisis of 1994 and was followed by the Russian crash of 1998 and the Brazilian crisis of 1999. This is another example of the way globalization can exacerbate rather than minimize the risk of total collapse.

This would not be the end of the world. The collapse of modern civilization would entail the deaths of billions of people but not the end of the human race. A few Mayans survived by abandoning their cities and retreating into the jungle, where they continue to live to this day. In the same way, some would survive the end of the industrial age by reverting to a pre-industrial lifestyle.

The enormity of such a scenario makes it hard to imagine. It is human nature to assume that the world will carry on much as it has been. But it is worth remembering that in the years preceding the collapse of their civilization, the Mayans too were convinced that their world would last forever.

Dylan Evans is a senior lecturer at the University of the West of England www.dylan.org.uk