Renowned conservationist Dr Jane Goodall has called for factory farming to be phased out as she condemned the “extreme cruelty” to animals involved.

The 89-year-old warned of agro-industries’ impact on human health, climate and biodiversity as she spoke in a video message at the Extinction or Regeneration Conference in London on Thursday.

The founder of the Jane Goodall Institute UK, which is among the conference partners, said: “Planet Earth is suffering as a result of our human activities.

“We’re making unsustainable demands on the natural world, having so believed there could be infinite economic growth on a planet with finite natural resources and a growing number of humans and livestock.”

She added that agro-industry is one of the major contributors to climate change and biodiversity loss, with “vast areas of land” cleared, a heavy reliance on chemical pesticides, and cramming billions of animals around the world into tiny spaces.

It comes as a new report, from conference partner Compassion in World Farming, revealed that massive reductions are needed across the top 25 high and upper-middle income countries to safeguard the future health of people, animals and the planet.

Dr Goodall warned that factory farmed animals emit a huge amount of greenhouse gases, as well as highlighting the adverse effects antibiotics and hormones used to raise animals in poor conditions may have on human health.

“The conditions of animals in factory farms are unacceptable,” she said. “Crammed into tiny spaces, they’re often treated with extreme cruelty.

“Secretly filmed videos reveal shocking scenes that kept me awake at night.

“It’s now proven that each animal, that the cow, pig, sheep, goat, rabbit, poultry or any other species used for food, is an individual, an individual capable of feeling depression, fear and pain.”

She said these sentient animals are treated as “unfeeling beings”, adding: “It seems clear then that factory farms should be phased out and if animals are farmed, they should be allowed to be out in the fields when the weather permits.”

Dr Goodall also called for intensive farming of crops, monocultures and agricultural chemicals to be phased out.

“We need to endorse small-scale family farming, regenerative farming and grow forestry permaculture and so on,” she said.

“And the good news is that a great deal of experimental work is being done in these fields and it’s proving that these methods of farming, working with rather than against nature, restoring biodiversity and helping to slow down climate change, truly can become sustainable and feed us for generations to come.”

Succession star Brian Cox, who also spoke via a video at the conference, warned that the “global food system is broken”.

“There are 820 million people across the world facing hunger yet a shocking one third of all food produced is lost or wasted between production and consumption each year,” he said.

“Over the past century we have willingly sleepwalked into a world of accelerating and biodiversity emergencies where people, animals and the planet suffer as a result of a system that is not fit for purpose.

“We need to find a way out before its too late. But there is hope, all of the people here today are here for the same reason – to find a pathway to a more positive future where collectively we work together to build a global food system that is sustainable for the sake of humans, animals and the future of our planet.”

The Compassion in World Farming report, released on day one of the conference, found that the UK needs to reduce meat consumption by 71%, dairy consumption by 56% and eggs consumption by 57%.

It also noted that the UK’s National Food Strategy failed to include reduction targets, despite the report commissioned to inform the strategy recommending a 30% reduction in meat consumption to meet the UK’s climate and nature commitments.

Iceland needs to make the biggest reduction across all animal-sourced foods, while the US needs to cut its overconsumption of meat by 82%, according to the research.

CIWF’s global chief executive Philip Lymbery told the conference: “Unless we wake up and act now to reduce this calamitous overconsumption, it will simply be too late.

“Responsibility lies with these richer nations to take immediate action through national policies to help combat their impact in driving the climate, health and nature emergencies.”