Wildlife and habitats are declining at an “unprecedented” rate worldwide which directly threatens human beings, a major new study has warned.

Up to a million species of plants and animals are at risk of extinction, a greater number than ever before in human history.

Species threatened with extinction(PA Graphics)

Many could vanish within decades, the UN-backed global assessment reveals.

Scientists warn that the natural world is deteriorating faster than ever as a direct result of human activity, eroding “the very foundations” of economies, livelihoods, food, health and quality of life worldwide.

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A huge transformation is needed across the economy and society to protect and restore nature, which provides people with food, medicines and other materials, crop pollination, fresh water, and quality of life.

Loss of pollinators such as bees is putting billions of pounds of crops at risk (Owen Humphreys/PA)Loss of pollinators such as bees is putting billions of pounds of crops at risk (Owen Humphreys/PA)

Without such “transformational change”, the damage will continue or worsen up to 2050 and beyond, posing a direct threat to human well-being around the world, the study said.

It will also undermine existing global efforts to tackle poverty and hunger, improve health and curb climate change.

The experts warned that “vested interests” would oppose changes to the status quo, from which they benefit through things such as subsidies or a lack of regulation, but this opposition could be overcome for the public good.

The three-year global assessment on the state of nature from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) has involved more than 450 experts from 50 countries.

It looked at changes to the natural world over the past five decades, during which time the human population has doubled and demand for energy and materials has increased significantly, and sets out scenarios for the future.

Habitats, wild animals and plants and even domesticated breeds are in decline or vanishing as a direct result of human activity, and the rate at which species are becoming extinct is accelerating.

The biggest cause of wildlife losses is change to the way land or marine environments are used, followed by direct exploitation of animals and plants, climate change, pollution and invasive species.

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Three-quarters of the world’s land has been “significantly altered” by human activity, with forests cut down and grassland ploughed up for crops or livestock and the spread of cities, industry and infrastructure such as roads.

Habitat is being destroyed by human activity (Emily Beament/PA)Habitat is being destroyed by human activity (Emily Beament/PA)

The study, which drew on thousands of pieces of evidence, also found that rising global temperatures were already having an impact on nature and the effects would increase in the coming decades.

Plastic pollution has increased 10-fold in the seas since 1980, harming turtles, seabirds and mammals, fertiliser run-off has caused “dead zones” in the oceans, land is becoming less productive, and the loss of pollinators puts crops at risk.

Leading British scientist and chairman of the IPBES Sir Robert Watson said: “The health of ecosystems on which we and all other species depend is deteriorating more rapidly than ever.

“We are eroding the very foundations of our economies, livelihoods, food security, health and quality of life worldwide.”

He added: “The report also tells us that it is not too late to make a difference, but only if we start now at every level from local to global.”

Professor Josef Settele, who co-chaired the assessment, said: “The essential, interconnected web of life on Earth is getting smaller and increasingly frayed.

“This loss is a direct result of human activity and constitutes a direct threat to human well-being in all regions of the world.”

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The report also found areas which are managed by indigenous people or local communities are under increasing pressure, but nature in them is generally declining less rapidly than elsewhere.

The assessment outlines a series of scenarios for the future, and found that major changes are required to protect nature and benefit people.

These include a shift away from concentrating on economic growth, bringing in wildlife-friendly farming, restoring habitats such as native forests, cutting food waste, creating marine protected areas and effective quotas for fishing, reducing pollution and creating more green space in cities.

It is hoped the evidence in the report will help form policies and action and provide the basis for new global targets to protect nature which will be negotiated at a UN meeting in China in 2020.