Global biodiversity have fallen below 'safe levels' which may have a negative impact on ecosystem function and the sustainability of human societies, according to a new study.
"This is the first time we have quantified the effect of habitat loss on biodiversity globally in such detail and we have found that across most of the world biodiversity loss is no longer within the safe limit suggested by ecologists," said Tim Newbold from University College London in the UK.
"We know biodiversity loss affects ecosystem function but how it does this is not entirely clear," said Newbold.
"What we do know is that in many parts of the world, we are approaching a situation where human intervention might be needed to sustain ecosystem function," he added.
Researchers found grasslands, savannas and shrublands were most affected by biodiversity loss, followed closely by many of the world's forests and woodlands.
According to them, the ability of biodiversity in these areas to support key ecosystem functions such as growth of living organisms and nutrient cycling has become increasingly uncertain.
Researchers found that levels of biodiversity loss are so high that if left unchecked, they could undermine efforts towards long-term sustainable development.
For 58.1 per cent of the world's land surface, which is home to 71.4 per cent of the global population, the level of biodiversity loss is substantial enough to question the ability of ecosystems to support human societies, researchers said.
The loss is due to changes in land use and puts levels of biodiversity beyond the 'safe limit' recently proposed by the planetary boundaries - an international framework that defines a safe operating space for humanity, they said.
"It is worrying that land use has already pushed biodiversity below the level proposed as a safe limit," said Andy Purvis from National History Museum London.
Researchers used data from hundreds of scientists across the globe to analyse 2.38 million records for 39,123 species at 18,659 sites.
The analyses were then applied to estimate how biodiversity in every square kilometre land has changed since before humans modified the habitat.
They found that biodiversity hotspots - those that have seen habitat loss in the past but have a lot of species only found in that area - are threatened, showing high levels of biodiversity decline.
"The greatest changes have happened in those places where most people live, which might affect physical and psychological wellbeing. To address this, we will have to preserve the remaining areas of natural vegetation and restore human-used lands," said Newbold.
The findings were published in the journal Science.
