“Chip is much more popular than me everywhere we go,” Chris Darwin says, jovially co-operating by posing for photos with the toy bald eagle he carries on his shoulder. “I nicked him from my children’s bedroom and he gets lots of attention.”

To meet Mr Darwin, laidback, cheerful and ultra-friendly, you would never guess he tried to commit suicide 26 years ago. He’s perfectly open about it, as much as he is passionate about his new work that sprang from the famous surname.

Mr Darwin’s great, great grandfather, Charles, may have developed the theory of the origin of species but today his descendant has picked up the evolutionary science baton to defend mass extinctions of species.

“We all have crucibles,” he says of the dark period when, aged 30, he tried to end his life by cycling over a cliff (he was saved by a random tree branch). “Critical moments when something normally bad happens that changes the rest of your life, and mine was this suicide event. Slowly I came to the concept that I needed purpose in life.”

Darwin the younger looked at all the world’s big problems – starvation, polluted water, disease – and settled on the crisis of mass extinctions as one he felt he wanted to help tackle. “So in 1991 I set off down that road.”

Bird man: Chris Darwin is making it his mission to halt wildlife decline (Jane Dalton)

When asked to what extent he was influenced by his legendary ancestor’s work in identifying the origins of man, he bursts into a roar of laughter. “It was entirely independent,” he insists in a voice heavy with irony.

Chris Darwin, 56, had come to London from his home in Australia for a groundbreaking conference attempting to tackle the growing crisis of the world’s rapidly diminishing wildlife, and one of the key causes of that loss – worldwide demand for meat.

More than 50 of the best minds in the fields of ecology, agriculture, public health, biology, oceanography, eco-investment and food retailing joined forces over two days to brainstorm ideas on how to stem the rapid shrinkage of the natural world caused by damaging agricultural practices.

The Extinction and Livestock Conference, with at least 500 delegates, was the world’s first ever conference examining how modern meat production affects life on Earth, and, put simply, it was designed to find ways to revolutionise the world’s food and farming systems to prevent mass species extinctions.

“We have to stop this,” says Mr Darwin, and he recalls how his great, great grandfather regretted on his death not having done more for other animals – a sentiment that shaped his decision to turn around his “self-indulgent, selfish” life, which involved working in advertising, and do something for the planet.

Wildlife under attack

The fact that the food on our plates is a major cause of shocking declines in wildlife – ranging from elephants and jaguar to barn owls, water vole and bumble bees – may come as a surprise to many. But for the experts gathered for the conference the link was clear. What was less easy to see was how to force practical global change.

Nobody can be in any doubt about the alarming rate at which animals, reptiles and birds are becoming extinct. The journal Science says we are wiping out species at 1,000 times their natural rate.

In the past 40 years alone half the world’s wildlife species have been lost, with conservation giant the World Wide Fund for Nature (WWF) predicting Earth is on course to lose two-thirds of its species within the next three years.

Marco Lambertini, director-general of WWF International, could not have put it more starkly: “Lose biodiversity, and the natural world – including the life-support systems as we know them – will collapse.”

Changing our spots: if we don't change our diets then animals, such as jaguar, face extinction (AFP/Getty)

The depth of the crisis was underlined earlier this year when scientists announced we were already living through an era of the world’s sixth mass extinction – caused by human activity. What was happening was so urgent, they warned, it should be termed not “mass extinction” but “biological annihilation”.

The researchers revealed, in the journal Nature, their findings that tens of thousands of species – including a quarter of all mammals and 13 per cent of birds – are now threatened with extinction. The researchers, who studied 27,600 species, said: “Dwindling population sizes and range-shrinkages amount to a massive anthropogenic erosion of biodiversity and of the ecosystem services essential to civilisation.”

And it’s not just land mammals that are disappearing. Last year a study in the journal Science suggested sharks, whales and sea turtles were dying in disproportionately greater numbers than smaller animals – the reverse of earlier extinctions.

The link with food

Climate change and hunting are usually blamed for declines in the natural world but at Extinction Conference 17, WWF revealed fresh research showing 60 per cent of global biodiversity loss is down to meat-based diets.

Its report, Appetite for Destruction, laid bare how the vast scale of cereals and soya grown specifically to feed animals farmed for meat is soaking up great tracts of land, taking huge quantities of fresh water and eliminating wild species.

What’s more, the study says, the world is consuming more animal protein than it needs: the average UK consumption of protein is between 64g and 88g, compared with guidelines of 45g-55g. Poultry such as chicken and duck are the biggest users of crop feed worldwide, with pigs second.

One study found that 60 per cent of EU cereal production (and 67 per cent in the US) is used as animal feed – yet for every 100 calories fed to animals as crops, we receive on average just 17-30 calories in the form of meat and milk.

It's a jungle out there: deforestation for food production is a massive problem (AFP/Getty)

According to the charity Compassion in World Farming (CiWF), the destructive practices were set in train after the Second World War, when intensive farming techniques spread from the US to Europe. Vast landscapes were replaced by “monoculture” – a single crop – in fields liberally treated with pesticides and fertilisers. They killed the insects, bees and butterflies at the bottom of the food chain and wiped away bird habitats, while active deforestation for food production is leaving ever smaller landscapes for mammals, from jaguar and elephants to polar bears and rhinos.

It’s happening in exotic locations – such as Indonesia, where the palm oil industry wrecks habitats and leads to elephants, porcupine and wild pigs being poisoned – and closer to home, where decades of use of nitrogen and other chemicals on farms has led to dire warnings about Britain’s soil having fewer than 100 harvests left.

But worldwide, the overwhelming problem, experts say, is the highly inefficient use of land to grow soya and cereals that are then fed to chickens, pigs and cattle slaughtered for meat.

According to The Economist, although livestock provides just 17 per cent of global calories consumed, it requires twice that proportion of the Earth’s fresh water, feed and farmland because of the crops required. And this makes it the greatest user of land in the world.

Philip Lymbery, chief executive of CiWF, which organised the conference, set out the causal links between modern intensive farming practices and the destruction of the natural world in his book Dead Zone, which explains how intensive rearing of animals in Britain and abroad to produce meat cheaply involves destroying forests half the size of the UK for farmland each year.

In South America, rainforests have been replaced by swathes of soya crops to feed cattle, pigs and chickens. Some 13 million hectares there – about the size of Greece – are used for soya imported by the EU, nearly all for industrial feed, according to WWF.

The system is so inefficient, says Lymbery, that “worldwide, if grain-fed animals were restored to pasture and the cereals and soya went to people instead, there would be enough for an extra four billion people”. Feeding animals on crops that are fit for humans is “the biggest single area of food waste on the planet”.

Sting in the tail: use of pesticides in fields is one of the factors leading to a decline in bees (CiWF) (Compassion in World Farming)

“Many people claim factory farming is the answer to feeding a burgeoning population but this couldn’t be further from the truth,” he says.

Intensively grazed landscapes, with fertilisers and pesticides and the demise of stubble, have led to steep declines in barn owls and other farmland birds and small mammals, while chemical run-off from fields is seen as a key cause of bee decline.

CiWF is not the only voice linking extinctions with our diets. The UN has stated that “intensive livestock production is probably the largest sector-specific source of water pollution”. The Soil Association says the UK’s food system accounts for 30 per cent of our greenhouse gas emissions, largely because of industrialised processes.

And WWF has warned: “We could witness a two-thirds decline in the half-century from 1970 to 2020, unless we act now to reform our food and energy systems and meet global commitments on addressing climate change, protecting biodiversity and supporting sustainable development.”

Solutions

Seven years ago, the UN Convention on Biological Diversity drew up a strategic plan, signed by 196 countries, of detailed targets for 2020 to slow wildlife decline. Since then scientists have repeatedly warned not just that the targets would be missed but also that biodiversity loss was worsening. The lack of action was one factor behind the Extinction Conference.

Lymbery said it should be the start of a “global conversation” on transforming food and farming worldwide, and called for a fresh UN convention. “To safeguard the future, we need some kind of global agreement to replace factory farming with a regenerative food system. But that’s not all. We all have the power, three times a day, to save wildlife and end an awful lot of farm animal cruelty.”

Mucking in: We have it in our power to prevent factory farming – by changing our behaviour (AFP/Getty)

Duncan Williamson, of WWF, proposed feeding farm animals on specially cultivated insects and algae, to dramatically reduce deforestation and water use needed as animal feed.

Food producers, meanwhile, showcased a new vegan burger that “sizzles and bleeds like meat”, endorsed by Joanna Lumley, the star of Absolutely Fabulous.

Less meat

Time and again, the solutions by conference experts led to a need to end industrial animal farming – which meant animal campaigners were suddenly no longer the only ones urging people to scale back drastically the amount of chicken, pork, beef, salmon, dairy and eggs consumed.

Chris Darwin, who spent six weeks on a container ship travelling to Britain to avoid flying, said: “Verifiable evidence indicates meat consumption globally will double in the next 35 years, and if that occurs so much forest will have to be cut down around the world that we’re going to cause a mass extinction of species within the next hundred years. And we cannot let that happen.”

He explained passionately how a typical diet uses “two-and-a-half planets” in terms of resources but cutting out wasteful animal produce uses “a quarter of the planet”.

Cut it out: Rainforests are being chopped down and replaced by soya crops (AFP/Getty Images)

He is using modern technology that would have astounded his great, great grandfather to fight back against the seemingly relentless decline of the natural world – in the form of an iPhone app helping people to switch to a more plant-based diet.

By tapping in what they eat, people can receive feedback over time on how many animals, carbon emissions and how much land and water they have saved, as well as days of lifespan added, and their placing on a leaderboard.