Scientists have warned that the wellbeing of human societies is threatened by the decline in levels of biodiversity.

A team of international researchers have issued a stark warning that humans could be under threat due to continued decline in biodiversity. Humans are highly connected to the wider ecosystem, and are increasingly threatened by changes in crop pollination, waste decomposition and the regulation of the carbon cycle, writes Robert Thompson for the BBC.

Biodiversity
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Biodiversity decline causes alarm for scientists

Ecosystems are dependent on biological diversity in order for processes to function. Research suggests that a loss of 10% of biodiversity places an area at risk, and a new report in Science claims that 58% of the world’s surface is already below this safe level.

In fact the global average of biodiversity has fallen to 85% compared to that of unaffected ecosystems. However defining the level of biodiversity loss that an ecosystem can withstand is a complicated process, which is variable between different ecosystems. As a result the 10% figure should be taken as a guideline, not a rule.

“Once we’re the wrong side of the boundary it doesn’t mean everything goes wrong immediately, but there is a markedly higher risk that things will go badly wrong,” said Prof Andy Purvis, a researcher on the report.

Report supported by other scientists

It is also risky trying to work out what the true figure is for a given ecosystem, as allowing further degradation by increasing the number could cause irreversible damage.

Owen Lewis, professor of ecology at Oxford University, supports the research although he was not part of the team. “This is definitely a situation where the precautionary principle needs to be applied: we can’t afford to wait to see the long-term consequences of degradation of natural ecosystems,” he said.

The researchers say that human intervention may now be required in order for ecosystem functions to be maintained. High levels of biodiversity loss have already been observed, and if the situation continues to worsen it could outweigh ongoing efforts towards sustainable development.

“The loss of biodiversity will reduce the resilience of ecosystems in the face of environmental changes such as global warming,” said Dr Tim Newbold, who is part of the research team.

Knowledge improved by detailed report

The report provides the most detailed analysis of global biodiversity that has ever been undertaken, with more than 1.8 million records. As such it gives us a good idea of how badly biodiversity is declining around the world.

“We hope that the report will inform policy makers and debate on how we use the Earth’s land,” said Dr Newbold.

Analysis undertaken by the time suggests that seven out of 14 biomes are now below the safe limit for biodiversity. The report reveals that savannahs, grasslands and shrublands are the worst affected.

“This is where a lot of the world’s farmland is currently,” explained Dr Newbold. “But many tropical biomes have also surpassed safe limits, and there is likely to be more farming in these biomes in the future.”

Among those least affected were tundra and boreal forests.

Australia is one country that is badly affected, with much of the country below the safe limit.

“Generally the most change in biodiversity has occurred in places where there are more people, but this isn’t always so,” said Dr Newbold. “In the case of Australia, the maps of the different land uses … suggest that a lot of Australia’s area is used for grazing livestock. This probably reflects reality to some extent, but is perhaps an overestimate [as] the extent of grazing land has proven difficult to estimate by global models.”