Growing populations and expanding economic activity have strained the planet's ecosystems over the past half century, a U.N.-sponsored study of the Earth's health warned.
  A fifth of coral reefs and a third of the mangrove forests have been destroyed. The diversity of animal and plant species has fallen sharply, and a third of all species are at risk of extinction. Disease outbreaks, floods and fires have become more frequent. Levels of  carbon  dioxide – a greenhouse gas – in the atmosphere have surged.
  Unless nations adopt more eco-friendly policies, increased human demands for food, clean water and fuels could speed the disappearance of forests, fish and fresh water reserves, it said. Eliminating trade barriers and subsidies, protecting forests and coastal areas, promoting "green" technologies and lower greenhouse gas emissions thought to contribute to global warming can all help to slow environmental degradation.
一項聯合國贊助的地球健康研究提醒，過去半世紀以來，全球人口增加與經濟活動擴展已損傷地球的生態系統。
  全球已有五分之一的珊瑚礁與三分之一的紅樹林受到破壞，動植物種類的多樣性急遽下滑，有三分之一的物種瀕臨絕滅，疾病爆發，水患與火災愈來愈頻繁，大氣層中溫室氣體二氧化碳的濃度上升。
  研究指出，除非各國採取對生態更友善的政策，否則人類對糧食、淨水與燃料的需求增加，將加速森林、魚類與淡水存量的消失。排除貿易設限與補貼、保護森林與海岸區、推廣「綠色」科技、減少造成全球暖化的溫室氣體排放等，皆有助於減緩環境惡化。