国内精品一区二区三区最新_不卡一区二区在线_另类重口100页在线播放_精品中文字幕一区在线

Humans have provoked the worst spate of extinctions since the dinosaurs were wiped out 65 million years ago, according to a UN report that calls for unprecedented worldwide efforts to address the slide.

 

The report paints a grim picture of life on earth, with declining numbers of plants, animals, insects and birds across the globe, and warns that the current extinction rate is up to 1,000 times faster than in the past. Some 844 animals and plants are known to have disappeared in the last 500 years.

 

Released on Monday to mark the start of a UN environment program meeting in Curitiba, Brazil, the report says: "In effect, we are currently responsible for the sixth major extinction event in the history of earth."

 

A rising human population of 6.5 billion is wrecking the environment for thousands of other species, it adds, and undermining efforts agreed at a 2002 UN summit in Johannesburg to slow the rate of decline by 2010. The global demand for biological resources now exceeds the planet's capacity to renew them by 20 per cent.

 

The report, Global Biodiversity Outlook 2 from the secretariat of the UN Convention on Biological Diversity, says: "The direct causes of biodiversity loss habitat change, over-exploitation, the introduction of invasive alien species, nutrient loading and climate change show no sign of abating."

 

It is bleaker than a first UN review of the diversity of life, issued in 2001, and says the 2010 goal can only be attained with "unprecedented additional efforts."

 

About 6 million hectares of primary forest are felled each year and about a third of mangrove swamps have been lost since the 1980s.

 

Up to 52 percent of higher bird species studied are threatened with extinction and the number of large fish in the North Atlantic has declined by two-thirds in the last 50 years.

 

The report concludes: "Biodiversity is in decline at all levels and geographical scales."

 

On the positive side, the number and size of protected areas is increasing, though most types of natural environment fall short of the target to protect 10 percent.

 

(China Daily March 22, 2006)