Plant-based diets, compassionate agriculture, Indigenous methods, consumer pressure, new laws, international agreements and even vegan pets - these are the solutions for fixing our broken food and farming systems, say dozens of environmental advocates, researchers, farmers and industry pioneers in a new book.

Editors Joyce D'Silva and Carol McKenna sound the alarm in their introduction to Regenerative Farming and Sustainable Diets, warning that 'our food system is broken'. Radical change is needed, they say, in our world where one‑third of food is lost or wasted, 780 million people are hungry, and three billion people cannot afford to eat healthily.

In this context, eminent researcher and author Philip Lymbery argues for an overarching UN Global Agreement to transform food systems. He warns: "We have just sixty harvests left in our soils to save the future for our children. For people, animals and the planet, the clock is ticking. There is no time to lose. What we do now will define the next one thousand years."

In his chapter, scientist Tim Benton illuminates how increased meat consumption has been a major driver of our planetary crisis: "As demand has risen - partly because of a growing global population but mainly owing to increased meat consumption and the associated increase in demand for animal feed - so too has the use of chemical inputs such as fertiliser, pesticides and herbicides to maximise yields on existing cropland... Nature has suffered as a result. Food production is therefore a central cause of declining biodiversity, deforestation, water and air pollution and land degradation."

But far from simply tolling a klaxon of doom, the authors of the book's chapters elicit hope by offering solutions for feeding the world, while nourishing our soils and protecting our species.

UK dairy farmer David Finlay charts his own path away from intensive agriculture and towards compassionate farming. Within just eight years, he has created a system which: produces bountiful milk, sees calves stay with their mothers and reach mature weight sooner, feeds cattle on leafy forage instead of mass-produced cereals, boosts farm biodiversity and has become 'climate positive'.

Indian scholar Vandana Shiva invites us to learn from the Indigenous peoples who protect 80% of the planet's biodiversity by looking after the 22% of the land still under their stewardship. She says: "We can bridge the climate change emissions gap through ecological agriculture now, not at some point in the future. Even if only 10% of farms and pastures are managed regeneratively by maximising photosynthesis and root exudates, we can mitigate emissions by fixing more living carbon in plants and building up carbon in soil. The solution to hunger extinction and the climate emergency is to return to Earth and regenerate her biodiversity in soils, our farms, forests, our diets and our guts."

British haematologist Shireen Kassam evidences the way plant-based diets boost both human and planetary health. She cites the EAT‑Lancet planetary health diet which suggests humans derive more than 85% of their energy from healthy plant foods. Such an approach has been shown to reduce deaths from all causes by more than 60% and reduce cancer rates by up to 40%.

But perhaps it's not just humans who should eat plant-based diets. In his chapter, researcher Andrew Knight argues for feeding cats and dogs a vegan diet. He says that the production of pet food contributes over a quarter of the livestock sector's environmental impact. And he calculates that if all of the world's cats and dogs were vegan "nearly seven billion fewer vertebrates would be killed".

Indeed, Knight presents evidence that if all the pet dogs in the world were vegan, it would save enough food to feed the entire population of the EU. And if all pet cats were vegan, it would save the same amount of greenhouse gas emissions as the whole of New Zealand emits.

But can our naturally carnivorous canine and feline housemates really lead healthy lives as vegans? Knight argues yes. He cites studies which have demonstrated that dogs and cats who are fed nutritionally-sound vegan diets have health at least as good, and in some respects better than, those fed meat‑based diets.

And while the various chapter authors largely sing in unison over the way forward, some strike different notes about which groups are best placed to bring about change.

Leon co-founder Henry Dimbleby - who has led two independent reviews for government - argues that we cannot rely on shoppers or farmers to drive change. Instead, he calls on governments to step up:

"We need new legislation to improve the lives of farm animals - a continuous ratcheting up of the standards we expect for factory farmed animals to relieve the cruelty we inflict upon them. It's no good expecting food producers or retailers to act voluntarily: the commercial incentives to produce cheap meat are simply too strong. Nor can we rely on consumer pressure. Although animal welfare ranks high amongst consumer concerns, most people have neither the time nor the information necessary to trace the provenance of all the meat they buy."

But the executive director of Waitrose, James Bailey, who nods approvingly to Dimbleby's work in his chapter, seems to disagree with him on this particular issue. Instead, he points at customers:

"Revolutionary change will only happen when it is demanded by shoppers. We need customers who understand what is at stake, willing to buy food produced in more sustainable ways that will probably be a bit more expensive. The reason that vegan food has quadrupled in shelf space in the last five years in the UK isn't because supermarket priorities have changed. It's because customer priorities have changed."

In her chapter, Lyla June Johnson, an expert in Indigenous food systems, urges us to learn from traditional methods, inspiring us to step up to the challenge:

"We do not need to settle for tiny orchards, nor do we have to simply let nature take its course. We can be active agents and participants in the way the land looks and tastes on massive, regional scales. Perhaps this signals to us as humans that we indeed have an ecological purpose in this world if we simply wield our energy in a regenerative manner."