Temps de lecture :3 minutes
PARIS: The human population is living far beyond its means and inflicting damage on the environment that could pass points of no return, according to a major report issued Thursday by the United Nations.
Climate change, the rate of extinction of species and the challenge of feeding a growing population are among the threats putting humanity at risk, the UN Environment Program said in its fourth Global Environmental Outlook since 1997.
“The human population is now so large that the amount of resources needed to sustain it exceeds what is available at current consumption patterns,” Achim Steiner, the executive director of the program, said in a telephone interview. Efficient use of resources and reducing waste now are “among the greatest challenges at the beginning of 21st century,” he said.
The program described its report, which is prepared by 388 experts and scientists, as the broadest and deepest of those that the UN issues on the environment and called it “the final wake-up call to the international community.”
Over the past two decades the world population has increased by almost 34 percent to 6.7 billion from 5 billion; similarly, the financial wealth of the planet has soared by about a third. But the land available to each person on earth had shrunk by 2005 to 2.02 hectares, or 5 acres, from 7.91 hectares in 1900 and was projected to drop to 1.63 hectares for each person by 2050, the report said.
The result of that population growth combined with unsustainable consumption has resulted in an increasingly stressed planet where natural disasters and environmental degradation endanger millions of humans, as well as plant and animal species, the report said.
Steiner said that demand for resources was close to 22 hectares per person, a figure that would have to be cut to between 15 and 16 hectares per person to stay within existing, sustainable limits. […]
Steiner said many of the problems identified by the Brundtland Commission were even more acute because not enough had been done to stop environmental degradation as flows of goods, services, people, technologies and workers had expanded, even to isolated populations. […]
Steiner said more intelligent management of scarce resources including fishing grounds, land and water was needed to sustain a still larger global population, which he said was expected to stabilize at between 8 billion and 10 billion people.
“Life would be easier if we didn’t have the kind of population growth rates that we have at the moment,” Steiner said. “But to force people to stop having children would be a simplistic answer. The more realistic, ethical and practical issue is to accelerate human well-being and make more rational use of the resources we have on this planet.“
Steiner said environmental tipping points, at which degradation can lead to abrupt, accelerating or potentially irreversible changes, would increasingly occur in locations like particular rivers or forests, where populations would lack the ability to repair damage because the gravity of a problem would be far beyond their physical or economic means.
Looking ahead, Steiner said parts of Africa could reach environmental tipping points if changing rainfall patterns stemming from climate change turned semi-arid zones into arid zones, and made agriculture that sustained millions of people much harder.
Steiner said other tipping points triggered by climate change could occur in areas like India and China if Himalayan glaciers shrank so much that they no longer supplied adequate amounts of water to populations in those countries. […]
Many biologists and climate scientists have concluded that human activities have become a dominant influence on the planet’s climate and ecosystems. But there is still a range of views on whether this could result in a catastrophic unravelling of natural resources as the human population heads toward nine billion by midcentury, or more of a steady diminution in diversity.
October 25th 2007