Veganism has seen an explosion in popularity in recent years, with many choosing a plant based diet for environmental reasons.
It’s widely acknowledged that meat and dairy production uses more land, energy, and water than growing plants. The consumption of animals also contributes towards deforestation, species extinction, and releasing billions of tonnes of greenhouse gases into the atmosphere each year.
“The planet can’t support billions of meat-eaters,” said David Attenborough in his documentary A Life On Our Planet, “If we had a mostly plant-based diet we could increase the yield of the land.
"The true tragedy of our time is still unfolding – the loss of biodiversity. Half of fertile land on Earth is now farmland, 70 per cent of birds are domestic, majority chickens. There’s little left for the world. We have completely destroyed it.”
However, vegan diets have been criticised – with some arguing it is better to buy local, organic produce including meat. So, let’s have a look at the evidence.
Why is meat and dairy bad for the environment?
Industrialised animal farming accounts for at least 14.5 per cent of all human-caused greenhouse gas emissions. That’s according to the UN, though some scientists believe the figure is higher – at least 16.5 per cent, or one sixth.
Beef is the highest contributor, creating 60kg of greenhouse gases per kg of meat produced. Indeed, cattle are responsible for 65 per cent of all livestock emissions.
This is due to the methane cows produce, but also the destruction of natural environments for their pasture, and their food. People often associate soy with a vegan diet, but the majority (80 per cent) of this crop is actually used for animal feed.
Beef and soy are the biggest contributors to habitat loss and deforestation in the world, according to the WWF.
The Intergovernmental Panel on Climate Change (IPCC )found that meat – especially from beef and lamb – was the single food with the greatest impact on the environment globally, in terms of greenhouse emissions and land use.
Is eating fish bad for the environment?
An estimated 30 per cent of all fish stocks are being overfished – meaning they are being caught faster than their populations can replenish.
This causes a devastating impact on ocean wildlife, with many species in decline and ecosystems threatened with collapse. It is estimated 50 million sharks, and 300,000 whales, dolphins, and porpoises are killed each year as bycatch from fishing.
Netflix documentary Seaspiracy claims the oceans will be virtually empty by 2048 if this continues. The film also argues there is no such thing as sustainable fishing and people should switch to a plant-based diet to allow oceans to recover.
Overfishing and bottom trawling – dragging a net indiscriminately along the sea bed – have also been linked to climate change. This is because the ocean is the world’s biggest carbon sink, absorbing more carbon than it releases, but fishing releases this greenhouse gas. Bottom trawling is said to release as much carbon as air travel.
Abandoned fishing gear is also responsible for the majority of the plastic pollution in the ocean. It is also the most deadly, able to kill marine life for decades or even centuries after it enters the sea – according to the WWF.
Is a vegan diet better for the environment?
If we all went vegan, food-related emissions could be cut by 70 per cent, an Oxford University study forecast in 2016. Studies also show that those with vegan diets have significantly lower carbon and water footprints.
While it is true some popular vegan products are bad for the environment, often animal products are worse.
For instance, at least 74 litres of water is needed to make a single glass of almond milk. But that is still less than for cow’s milk, at 120 litres.
Studies have found a vegan diet would have the biggest impact on cutting emissions in the atmosphere. The IPCC found a global switch to veganism could cut eight gross tonnes of CO2 from the atmosphere, whereas a “climate carnivore” – someone who cuts red meat by 75% – would cut just over three gross tonnes.
Is buying local meat and dairy better for the environment than going vegan?
Buying local meat is often suggested as a more environmentally friendly alternative to going vegan.
Here in the UK, agriculture in general is more sustainable than many other countries. It accounts for 10 per cent of the UK’s total greenhouse emissions, according to a 2019 DEFRA report.
Why is this? First of all, the land used for farming is not being deforested, as this already happened hundreds of years ago.
Also, most cows are grass fed throughout the summer and eat hay, straw, or silage in the winter. The grass also serves as a ‘carbon sink’, absorbing CO2 from the atmosphere.
But livestock here still consumes a significant amount of soy. Two million tonnes of it was reported to have been imported here for animal feed in 2018.
Another issue is the methane produced by cattle. DEFRA reported 25.7 million tonnes of it was released into the atmosphere in 2017 – about half of UK agriculture’s total greenhouse emissions.
UK farmers are working to become more sustainable, with the National Farmers Union (NFU) pledging to hit Net Zero by 2040. It aims to do this by ‘capturing’ more carbon in the air to balance out their negative emissions.
The UN estimates that, by making livestock farming more efficient, emissions could be cut by 30 per cent.
So, what’s the verdict?
Scientists are not wholly in agreement on this subject – but most do agree that the global food system is unsustainable in its current form.
One thing is clear: it would make a significant difference to the planet if humans cut down their consumption of meat and dairy, and adapted to sustainable farming methods.
Read more on this subject:
- The IPCC: Impacts of Food Systems on Climate Change
- Carbon Brief: What is the climate impact of eating meat and dairy?