Global ecological disaster predicted in next 50 years
http://www.100md.com
《英国医生杂志》
Humanity is heading for ecological disaster if instead of foreseeing and preventing environmental degradation we just react to it. This is the conclusion of a United Nations report compiled by 1300 leading scientists from 95 countries.
The Millennium Ecosystem Assessment Synthesis Report previews the ecological state of the world in 2050. It lists 24 essential "ecosystem services," such as timber, clean air, and fresh water, and finds that 60% of them are being degraded or used unsustainably.
This degradation obstructs the UN Millennium Development Goals, set in 2000, the most ambitious of which was a halving of the world's population existing on less than a $1 (￡0.53; 0.78) a day or threatened by hunger or lack of clean water. Among the gravest threats to the environment are excessive "nutrient loading" from agricultural fertilisers and the progressive disappearance of biodiversity. The extinction rate of species is already a thousand times higher than the average rate shown by the fossil record and is set to increase 10-fold in the next 50 years.
"Humans are fundamentally and to a significant extent irreversibly changing the diversity of life on earth," says the report, noting that this could harm pharmaceutical research and development.
The scientists warn of possible "accelerating, abrupt, and potentially irreversible changes." These include the collapse of fish stocks, such as North Sea cod; rapid growth of marine algae, creating oxygen depleted dead zones in the sea; and emergence of disease.
Slash and burn agriculture is destroying this rain forest in Cameroon
Credit: FRED HOOGERVOORST/PANOS
In Africa, growing pressure on water supplies combined with regional climate change has the potential to greatly enlarge the areas in which cholera is a threat. The range of malaria bearing mosquitoes is also likely to increase.
The release of carbon into the atmosphere and the leaching of nitrogen based fertilisers into water pose serious risks for chronic disease, the report finds. Increases in ultraviolet B radiation, ozone and other air pollution, and pollen production are also predicted.
The report gives four sets of predictions for 2050, based on the approach currently adopted to counter ecosystem degradation. "The scenario we are closest to now is the one we call order from strength," said Dr Reid. This describes a world in which international cooperation is lacking, economic competition is fierce, and environmental threats are faced only after they emerge. This is likely to deliver the fastest population growth, the lowest economic growth, and the most environmental damage of the four scenarios, he said.(Owen Dyer)
The Millennium Ecosystem Assessment Synthesis Report previews the ecological state of the world in 2050. It lists 24 essential "ecosystem services," such as timber, clean air, and fresh water, and finds that 60% of them are being degraded or used unsustainably.
This degradation obstructs the UN Millennium Development Goals, set in 2000, the most ambitious of which was a halving of the world's population existing on less than a $1 (￡0.53; 0.78) a day or threatened by hunger or lack of clean water. Among the gravest threats to the environment are excessive "nutrient loading" from agricultural fertilisers and the progressive disappearance of biodiversity. The extinction rate of species is already a thousand times higher than the average rate shown by the fossil record and is set to increase 10-fold in the next 50 years.
"Humans are fundamentally and to a significant extent irreversibly changing the diversity of life on earth," says the report, noting that this could harm pharmaceutical research and development.
The scientists warn of possible "accelerating, abrupt, and potentially irreversible changes." These include the collapse of fish stocks, such as North Sea cod; rapid growth of marine algae, creating oxygen depleted dead zones in the sea; and emergence of disease.
Slash and burn agriculture is destroying this rain forest in Cameroon
Credit: FRED HOOGERVOORST/PANOS
In Africa, growing pressure on water supplies combined with regional climate change has the potential to greatly enlarge the areas in which cholera is a threat. The range of malaria bearing mosquitoes is also likely to increase.
The release of carbon into the atmosphere and the leaching of nitrogen based fertilisers into water pose serious risks for chronic disease, the report finds. Increases in ultraviolet B radiation, ozone and other air pollution, and pollen production are also predicted.
The report gives four sets of predictions for 2050, based on the approach currently adopted to counter ecosystem degradation. "The scenario we are closest to now is the one we call order from strength," said Dr Reid. This describes a world in which international cooperation is lacking, economic competition is fierce, and environmental threats are faced only after they emerge. This is likely to deliver the fastest population growth, the lowest economic growth, and the most environmental damage of the four scenarios, he said.(Owen Dyer)