杏吧原创

The world鈥檚 major ecosystems are buckling under the strain of human activity.
So says an exhaustive, two-year study by 175 scientists from the World Resources
Institute and several UN agencies. They say half the world鈥檚 wetlands
disappeared in the past century; forestry and agriculture have gobbled up half
the world鈥檚 original forests; and fishing fleets are 40 per cent larger than the
ocean can sustain. World Resources 2000-2001 warns that 鈥渉alting the
decline of the planet鈥檚 life-support systems may be the most difficult challenge
humanity has ever faced鈥�.