The noisy anti-livestock farming lobby has been handed a new weapon with the United Nations proposing new taxes aimed largely at reducing red meat consumption.
In its latest global environment outlook (GEO) statement the UN Environment Secretariat concludes livestock farming will need to contract significantly worldwide to meet the challenge of feeding nine to 10 billion people by 2050 without destroying the environment.
The report said less-meat intensive diets and slashing food waste in both developed and developing countries would help reduce the need to lift food production by an estimated 50 per cent to meet population growth by mid-century.
The report, which was produced by 250 scientists and experts from more than 70 countries, said agriculture's environmental footprint had to be reduced and one way of achieving that was to lift retail prices of red meat through consumption taxes.
The UN report said such a tax could save one billion tonnes of carbon dioxide-equivalent per year.
It said land management practices had to change to feed the world's swelling population while preserving ecosystem services, stemming the loss of natural habitat, combating climate change and addressing water and energy security.
Overall, climate change would reduce rainfall and agricultural output although higher temperatures and carbon dioxide levels would boost production in some regions.
Food production now accounted for 50pc of habitable land. The livestock sector provided 17pc of dietary energy and 33pc of dietary protein demands, yet occupied 77pc of agricultural land for feed, pasture and grazing, the report said.
"Therefore using 80pc of the land for livestock is inefficient," the report said.
The report also highlighted unacceptable global food waste with one third of food for human consumption now lost or wasted including 56pc in industrialised countries.
Its recommendation for taxes to reduce red meat consumption will add more fuel to growing attacks on livestock farming by activists groups, scientists and media commentators.
Twitter is now awash with often bitter verbal clashes between livestock farmers and anti-meat campaigners.
The "war on meat" is being fought on a number of battlefronts including the contribution of cattle to greenhouse gas emissions (hotly disputed by a number of livestock scientists), the alleged impact of consumption on human health and obesity as well as on animal welfare grounds.
Animal activists are becoming increasingly bold by invading livestock farms, particularly intensive operations, largely for publicity reasons.
It would also come as no surprise that PETA, the radical animal activist group, is a supporter of a tax on all meat (including fish).
PETA has said meat should be treated the same as cigarettes, alcohol and fuel and be taxed to reduce its alleged impacts on the health of both humans and the climate.
Dozens of countries have now introduced taxes on sugar on the back of relentless publicity about its contribution to worldwide obesity.
The livestock sector is also feeling heat from the headline-grabbing proliferation of plant-based and lab-grown alternatives to farm-reared meat.
Beyond Meat, a cult US-based producer of plant-based meat substitutes, is supported by a number of celebrity investors including Bill Gates and Leonardo DiCaprio.
In January Nestlé announced plans to introduce a plant-based burger called the "Incredible Burger".
Dutch company, Vivera, launched a plant-based "steak" in May last year through Europe's largest supermarket chain, Tesco.
Last year Israeli start-up, Aleph Farms, claimed it had produced the world's first cell-grown beef steak.
Dutch food technology company, Mosa Meat - whose founder, Mark Post, created the world's first lab-grown hamburger in 2013 - is pressing on with the development of commercial meat products using cell-culture technologies.
The company is growing cow cells in a laboratory to produce "real" meat.
