Countries are gathering to negotiate what is hoped will be a global deal to reverse and halt declines in nature, in the face of a crisis that threatens humanity.

The Chinese-chaired “Cop15” global biodiversity conference kicks off in Montreal, Canada this week, and campaigners have called for a deal similar to the historic Paris Agreement secured in 2015 to tackle climate change.

While the collapse of nature may be the less-well known sister problem to the climate crisis, the figures showing what people are doing to the planet are no less stark.

A UN-backed study released ahead of the original 2020 date for the conference – before the pandemic hit – showed up to a million species were at risk of extinction, many within decades.

The scientists warned that the natural world is deteriorating faster than ever as a direct result of human activity, including the clearing of forests and other habitats for crops and livestock, pollution, direct exploitation of wildlife, invasive species and increasingly climate change.

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

That in turn is eroding “the very foundations” of economies, livelihoods, food, health and quality of life worldwide – all of which relies on healthy natural systems.

Separately, scientists have warned that increased exploitation of nature and habitats is raising the risk of diseases, such as the coronavirus that caused the pandemic, jumping from wildlife to humans.

Mangroves by the water in Gabon
Mangroves provide shelter for wildlife, store carbon and protect coastal areas from storms (Emily Beament/PA)

And the most recent Living Planet assessment from conservation charity WWF and the Zoological Society of London (ZSL) found global wildlife populations have fallen by nearly 70% in less than 50 years.

The study published in October also warned the Amazon is reaching a tipping point where it will cease to be a functioning rainforest, without which the world cannot avert dangerous warming.

The UK is no exception when it comes to loss of wildlife and habitat – it has been described as one of the most nature-depleted countries on Earth, with once-common wildlife such as skylarks and hedgehogs now rare, and 97% of wildflower meadows lost.

Other countries are already facing the consequences of the collapse in nature:  in Ghana, for example, the government is having to train people to laboriously hand-pollinate cocoa plants following widespread use of pesticides.

While global action to tackle nature loss falls under a different UN treaty from climate change, the two crises are closely interlinked.

Scientists estimated in the 2019 report that about a quarter of greenhouse gas emissions are caused by clearing land such as forests, growing crops and using fertilisers, largely to produce meat and dairy.

In turn, climate change is threatening wildlife and habitats on which millions of people rely, such as coral reefs that provide food and protection from storms and which are set to all but disappear with 2C of global warming.

Tackling the two crises are also interlinked: for example restoring native, diverse forests supports wildlife and absorbs carbon emissions.

Farming in a more nature-friendly way – from reducing chemical use to creating healthy soils and bigger hedgerows – cuts carbon emissions, boosts wildlife include pollinator and predators that feed on pests and can improve productivity.

Restoring species such as beavers to Britain creates wildlife-rich wetlands that improve water quality and store carbon, and help reduce flooding and conserve water in drought, which are worsening with climate change.

Even boosting whale numbers, whose carcasses sink carbon to the ocean floor and whose poo supports phytoplankton that capture carbon, helps the climate and marine wildlife – and in turn supports fish stocks and livelihoods such as ecotourism.

Craig Bennett, chief executive of The Wildlife Trusts, said: “We rely on nature for everything – from producing food and economic prosperity to regulating our climate.

“Cop15 comes at a critical moment – our future on earth relies on restoring natural habitats to store carbon and help us adapt to climate change.

“World leaders must agree legally binding targets for nature’s recovery, and quickly develop plans for how that will be achieved.

“If not, we could see the collapse of whole ecosystems and a huge number of species go extinct.”

On the table at the talks is a deal to halt and reverse the declines in nature, with countries including the UK pushing for targets including protecting 30% of the world’s land and seas by 2030, halting species extinctions and supporting finance flows to help pay for it.

But countries do not have a good record when it comes to tackling nature loss: a previous raft of goals set in Aichi, Japan, in 2010, were not met, so the pressure is also to make sure any new targets are delivered on.

WWF chief executive Tanya Steele said the “stakes are high and time is running out” for saving humanity’s own life support system.

“This summit is a chance the world must not miss to agree a global deal to reverse nature loss, just like the historic Paris climate deal to limit global warming.

“World leaders, including UK Prime Minister Rishi Sunak, must step up to deliver a landmark agreement for nature to bring our world back to life,” she urged.

Friends of the Earth campaigner Paul de Zylva added: “As one of the most nature-depleted nations, the UK needs to put its own house in order by helping farmers, landowners, developers and businesses to thrive without continuing to push nature to the edge.”