In Lester Brown's new book "World on the Edge," he says mankind has pushed civilisation to the brink of collapse by bleeding aquifers dry and overploughing land to feed an ever-growing population, while overloading the atmosphere with carbon dioxide.
If we continue to sap Earth's natural resources, "civilisational collapse is no longer a matter of whether but when," Brown, the founder of Worldwatch and the Earth Policy Institute, which both seek to create a sustainable society, said.
What distinguishes "World on the Edge" from his dozens of other books is "the sense of urgency," Brown said. "Things could start unravelling at any time now and it's likely to start on the food front.
"We've got to get our act together quickly. We don't have generations or even decades, we're one poor harvest away from chaos," he said.
"We have been talking for decades about saving the planet, but the question now is, can we save civilisation?"
In "World on the Edge", Brown points to warning signs and lays out arguments for why he believes the cause of the chaos will be the unsustainable way that mankind is going about producing more and more food.
Resources are already beginning to be depleted, and that could cause a global "food bubble" created by overusing land and water to meet the exponential growth in demand for food - grain, in particular - to burst.
Two huge dustbowls have formed in the world, one in Africa and the other in China and Mongolia, because of soil erosion caused by over ploughing.
In Lesotho, the grain harvest has dropped by more than half over the last decade or two because of soil erosion, Brown said.
In Saudi Arabia, grain supplies are shrinking as a fossil aquifer drilled in, in the 1970s to sustain domestic grain production is running dry after years of "over pumping" to meet the needs of a population that wants to consume more meat and poultry.
Other impacts on grain supply
Global warming is also impacting the global supply of grain, which Brown calls the foundation of the world food economy.
Every one-degree-Celsius rise above the normal temperature results in a 10% fall in grain yields, something that was painfully visible in Russia last year, where a seven-week heatwave killed tens of thousands and caused the grain harvest to shrink by 40%.
Food prices soared in Russia as a result of the poor harvest, and Russia, which is one of the top wheat exporters in the world, cut off grain exports.
Different grains are staple foods in most of the world, and foods like meat and dairy products are "grain-intensive."
It takes 3.2 kilograms of grain fed to a cow to produce a pound of beef, and around 1.8 kilograms of grain to produce a pound of cheese, Brown said.
Painting a grim picture
In "World on the Edge", Brown paints a grim picture of how a failed harvest could spark a grain shortage that would send food prices sky-rocketing, cause hunger to spread, governments to collapse and states to fail.
Food riots would erupt in low-income countries and "with confidence in the world grain market shattered, the global economy could start to unravel," Brown warned.
But Brown still believes civilisational collapse can be averted, if there is a mass effort to confront threats such as global warming, soil erosion and falling water tables, not military superpowers.
(Sapa, Karin Zeitvogel, January 2011)
Is planting trees stupid?
Organic food: no real benefits?