The variety of animals and plants has fallen to dangerous levels across more than half of the world’s landmass, scientists have estimated. The unchecked loss of biodiversity is akin to playing ecological roulette and will set back efforts to bring people out of poverty in the long term, they warned. Analysing 1.8m records from 39,123 sites across Earth, the international study found that a measure of the intactness of biodiversity at sites has fallen below a safety limit across 58.1% of the world’s land. Under a proposal put forward by experts last year, a site losing more than 10% of its biodiversity is considered to have passed a precautionary threshold, beyond which the ecosystem’s ability to function could be compromised. “It’s worrying that land use has already pushed biodiversity below the level proposed as a safe limit,” said Prof Andy Purvis, of the Natural History Museum, and one of the authors. “Until and unless we can bring biodiversity back up, we’re playing ecological roulette.” Researchers said the study, published in the journal Science on Thursday, was the most comprehensive examination yet of biodiversity loss. The decline is not just bad news for the species but in the long term could spell problems for human health and economies.
“If ecosystem functions don’t continue, then yes it affects the ability of agriculture to sustain human populations and we simply don’t know at which point that will be reached,” said Dr Tim Newbold, lead author of the work and a research associate at University College London. “We are entering the zone of uncertainty.”
Source: The Guardian, 14 July 2016