Biodiversity plunges below 'safe' levels: study

Having a range of different plant and animal species helps guarantee the health of the Earth, but a study Thursday suggested that biodiversity may be declining beyond safe levels. On 58 percent of the world's land surface, which is home to 71 percent of the global population, "the level of biodiversity loss is substantial enough to question the ability of ecosystems to support human societies," said the report in the US journal Science. Researchers at University College London based their study