One million species are now at risk of extinction while three-quarter of the world’s food comes from just 12 plants and five animal species. We are destroying the Earth’s rich biodiversity for the sake of a burger and a shake.
The production of meat, fish and dairy is having have a disastrous impact on wildlife through overgrazing, overfishing, deforestation, land degradation and desertification – all driven by the insatiable demand for animal foods.
We are now living through the world’s sixth mass extinction but this time it’s of our own making. Loss of habitats and species extinction are taking place at a rate unprecedented in human history. Going vegan could halt this destruction and give the world’s wildlife a chance to recover.
Arguably the most serious aspect of the environmental crisis is the loss of biodiversity – the other living things with which we share Earth (Ceballos et al., 2015).
Biodiversity refers to all terrestrial, marine and other aquatic species of plant and animal, the genetic diversity between them and the ecosystems they inhabit (FAO, 2018). It’s short for ‘biological diversity’ and even includes microorganisms such as bacteria, viruses and fungi. In other words, biodiversity is the amazing variety of life on Earth.
Biodiversity is key to food security and nutrition (FAO, 2018).
So why does biodiversity matter?
So why does it matter? Some examples are obvious – without plants there would be no oxygen and without bees to pollinate plants there would be no fruit or nuts. We know that tress in the city can help combat pollution. Other examples are less obvious – large-fruit-eaters, such as tropical tortoises and spider monkeys, help maintain a stable climate by dispersing the seeds of the dense, hardwood trees that are most effective in removing carbon dioxide from the atmosphere.
“Without biodiversity, there is no future for humanity” says David Macdonald, Professor of Wildlife Conservation and Director of the Wildlife Conservation Research Unit at Oxford University.
How dependent one part of a complex ecosystem is on another may not be apparent until it is lost. Think of biodiversity like a knitted jumper – pulling out a loose thread may not cause a serious problem or it may unravel the entire jumper.
The role of livestock
Habitat degradation and land use change are among the major factors causing biodiversity loss and livestock farming is at the heart of this environmental catastrophe.
Species-rich habitats are being converted to pasture and feed crops for livestock as the human appetite for meat grows. As forests, woodlands, hills and savannas are taken over, either for grazing or for growing animal feed crops, native plant and animal species and their habitats are being lost at an unprecedented rate.
A study published in the Science of the Total Environment shows how livestock production is pushing pastures and cropland into areas of high biodiversity. Many of the places seeing the greatest shift in land use, from forest to livestock, are in countries with the largest number of species. By 2050, given current trends, these countries will likely increase the land used for livestock by 30-50% (Machovina et al., 2015). This study provides a direct link between livestock farming and loss of biodiversity.
Monocultures and mega farms
Over the last 50 years or so, an increasingly small numbers of plant and animal species have been selected for uniformity and suitability to intensive farming methods – global food production is now dominated by just a handful of species. In other words, most of the food we eat comes from a limited number of plants and animal species which are being farmed in in huge monocultures and mega farms.
Three quarters of the world’s food is generated from just 12 plant and five animal species (FAO, 2004).
The global chicken population is now almost 22 billion – more than three chickens for every single person. If you weighed the global cattle population, that too would be greater than the weight of all humans (Bailey et al., 2014). At current levels of consumption, such massive livestock populations have profound consequences for biodiversity because of deforestation, change of land use, overgrazing, degradation of grasslands and desertification (Bailey et al., 2014).
The impact of meat and dairy
The environmental impact of meat and dairy products far exceeds that of plant-based foods – meat, fish, eggs and dairy use around 83% of the world’s farmland and contribute 56-58% of food’s different emissions but only provide 37% of the protein we eat and 18% of calories (Poore and Nemecek, 2018). The human appetite for meat and dairy products comes at a high price.
The global demand for animal foods is expected to increase substantially, driven by a growing global population, increased prosperity and a shift in dietary patterns. If trends continue, greenhouse gas and nitrogen emissions from livestock farming will rise and cropland and grassland areas could expand by 10-20% over the coming decades, leading to significant losses of biodiversity, especially in South Asia, Sub-Saharan Africa and South America (Westhoek et al., 2011).
Another kind of road kill
Researchers writing in the journal Trends in Ecology and Evolution issued a stark warning when they described what is happening in our rainforests. Characterised by uniquely dark, humid and stable microclimates, rainforests sustain many species suited to the interior of the forest that shy away from the forest edges and are unable to cross clearings. Large numbers of beetles, flies, ants, bees, butterflies, amphibians, reptiles, birds, bats, small and large mammals avoid even narrow clearings. New roads, highways, power lines and gas lines are rapidly expanding in tropical forests and can increase habitat fragmentation, road kill, hunting (bush-meat harvesting), as well as forest fires.
These clearings also enable species invasion, of for example, fire ants, earthworms, non-forest vertebrates and various weeds. Little fire ants spreading through African rainforests 60 times faster along logging roads than through undisturbed forest can kill or blind native species such as monkeys, apes, leopards, and insects. The authors of this study warn: “As Pandora quickly learned, it was much harder to thrust the evils of the world back into the box, than to simply not open it in the first place” (Laurance et al., 2009).
Wilderness areas are disappearing
Wilderness (uncultivated) areas tend to contain the richest levels of biodiversity. However, the Earth’s wilderness areas are disappearing at a faster rate than attempts to protect them can keep pace with. Catastrophic declines in wilderness areas around the world have occurred in recent years. Around 20% (30.1 million km2) of the world’s land area is wilderness, mostly in North America, North Asia, North Africa and the Australian continent. Since the 1990s,
10% (3.3 million km2) of this wilderness land has been lost – an area twice the size of Alaska and half the size of the Amazon (Watson et al., 2016).
Between 1993 and 2009, the extent of Earth’s wilderness areas has been reduced by 30% in South America, 14% in Africa and 10% globally (Watson et al., 2016).
Dr James Watson, of the University of Queensland in Australia and the Wildlife Conservation Society in New York, says: “If we don’t act soon, there will only be tiny remnants of wilderness around the planet, and this is a disaster for conservation, for climate change, and for some of the most vulnerable human communities on the planet”.
For decades scientists have been warning that human activity is pushing life on our shared planet toward a sixth mass extinction. Natural ecosystems are degrading at a rate unprecedented in human history.
Wildlife populations in decline
Every two years, the World Wide Fund for Nature (WWF) publishes its Living Planet report providing information on which habitats and ecosystems are declining most rapidly. The 2016 edition says: “Wildlife populations have already shown a concerning decline, on average by 58 per cent since 1970 and are likely to reach 67 per cent by the end of the decade” (WWF, 2016).
In terms of biodiversity loss, most attention is focused on rainforests. Savannahs and grasslands (grassy biomes) are considered poor cousins of the tropical rainforest. However, in areas of high rainfall, the diversity of vertebrates in grassy biomes can be just as high as in rainforests. These biomes should be recognised as a critical, but increasingly threatened, store of global biodiversity (Murphy et al., 2016).
British mammals in decline
In Britain, at least one in five wild mammals faces a high risk of extinction within a decade and overall populations are falling. Most at risk are the Scottish wildcat and black rat (which may already be extinct). In 2018, there was only a single male greater mouse-eared bat left who was last seen living alone in a railway tunnel in West Sussex. Other species at risk include hedgehogs, rabbits and water voles. The most numerous species is the field vole at 60 million, followed by the mole, at 41 million. Both are outnumbered by livestock, with 44 million sheep and cattle (combined) and 181 million chickens (Mathews et al., 2018).
Switching from meat to fish is not the answer. Biodiversity loss on land is linked to livestock production and its contribution to desertification, overgrazing and degradation of grasslands, deforestation and change of land use. However, livestock production also leads to substantial emissions of nitrogen in various forms (ammonia, nitrates), which in turn lead to losses of both land and aquatic (including marine) biodiversity.
Marine species under threat
Marine and freshwater biodiversity is under threat and wild fish stocks are in decline. Globally, marine fish populations have declined by 24% since 1950. About 80% of commercial fish populations are fully exploited or overexploited (that means close to its maximum sustainable yield or over it respectively). In the same way that increasing meat production is harming biodiversity of land animals and plants, increasing fish consumption would have an unfavourable impact on marine biodiversity (Westhoek et al., 2011).
Marine species (seabirds, marine mammals, sea turtles and fish) have declined by 36% between 1970 and 2012 with an average decline of 1% per year (WWF, 2016).
The European Council in March 2010 agreed on “a headline target of halting the loss of biodiversity and the degradation of ecosystem services in the EU by 2020, and restoring them in so far as feasible, while stepping up the EU contribution to averting global biodiversity loss” (Westhoek et al., 2011). However, if current trends continue, targets will be increasingly difficult to meet. The WWF says that we are already off track for reaching UN biodiversity targets aiming to halt the loss of biodiversity by 2020 (WWF, 2016).
Losses of habitats and species extinction are taking place at an alarming rate: up to 100,000 species go extinct every year (WWF, 2015).
Extent of loss unknown
It’s hard to estimate precisely how many species are being lost as we don’t know exactly what’s out there – new species are being discovered all the time. If the upper estimate of species numbers is true (that there are 100 million different species co-existing with us on our planet) then between 10,000 and 100,000 species are becoming extinct each year (WWF, 2015).
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species is the world’s most comprehensive inventory of the global status of plant and animal species. Species are classified as: extinct, extinct in the wild, critically endangered, endangered, vulnerable, near threatened, least concern, data deficient and not evaluated.
Currently there are over 79,800 species on the IUCN Red List, of which more than 23,000 are threatened with extinction, including 41% of amphibians, 34% of conifers, 33% of reef building corals, 25% of mammals and 13% of birds (IUCN, 2017). The basic message is that, whatever the threat category or species group, overexploitation and agriculture have the greatest current impact on biodiversity (Maxwell et al., 2016).
Of all the plant, amphibian, reptile, bird and mammal species that have gone extinct since AD 1500, 75% were harmed by overexploitation or agricultural activity or both (Maxwell et al., 2016).
Writing in the journal Nature, a team from the University of Queensland, the Wildlife Conservation Society and the IUCN assessed 8,688 near-threatened or threatened species on the IUCN’s ‘red list’ against 11 threats: overexploitation, agricultural activity, urban development, invasion and disease, pollution, ecosystem modification, climate change, human disturbance, transport and energy production.
Most of the species looked at were affected by more than one threat. However, they found that overexploitation and agricultural activity were by far the most prevalent threats facing these threatened or near-threatened species (Maxwell et al., 2016).
Expansion of agriculture
They said the expansion of agriculture is threatening 5,407 species (62% of those listed as threatened or near-threatened). Africa’s cheetah, Asia’s hairy-nosed otter and South
America’s huemul deer were among more than 2,300 species affected by livestock farming and aquaculture. The Fresno kangaroo rat and the African wild dog are two of more than 4,600 species under threat from land use changes associated with the production of food, animal feed or biofuels (Maxwell et al., 2016).
Climate changes (increases in storms, flooding, extreme temperatures, drought and sea-level rise) affected 19% of species listed as threatened or near-threatened. Hooded seals were among the 1,688 species affected and have dropped in abundance by 90% in the North-eastern Atlantic Arctic over the past few decades (Maxwell et al., 2016).
Nature is declining warns UN
The IUCN Red List of Threatened Species was key in informing a landmark new report from the United Nations Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). The report found that around one million animal and plant species are now threatened with extinction, many within decades, more than ever before in human history (United Nations, 2019).
“Nature is declining globally at rates unprecedented in human history – and the rate of species extinctions is accelerating, with grave impacts on people around the world now likely” (United Nations, 2019).
The UN report was compiled by 145 expert authors from 50 countries over three years, with inputs from another 310 contributing authors. It assessed changes over the past five decades and offers a range of possible scenarios for the coming decades.
The report says it is not too late to make a difference, but only if we start now at every level from local to global. Through ‘transformative change’ the report says, nature can still be conserved, restored and used sustainably.
Scientists describe mass extinctions as times when the Earth loses more than three-quarters of its species in a geologically short interval. This has happened only five times in the past 540 million years or so. Biologists now suggest that a sixth mass extinction may be under way, given the known species losses over the past few centuries and millennia (Barnosky et al., 2011).
Writing in the Proceedings of the National Academy of Sciences, scientists investigated nearly half of all known vertebrate species and found that 32% (8,851 out of 27,600) had decreased in population size and range. In the 177 mammals they had detailed information for, all had lost 30% or more of their geographic ranges and more than 40% had experienced severe population declines. They said that Earth is experiencing a huge episode of population declines, which will have negative cascading consequences on ecosystem functioning and services vital to sustaining civilisation. They describe this as a ‘biological annihilation’ to highlight the current magnitude of Earth’s ongoing sixth major extinction event (Ceballos et al., 2017).
Meat – the challenge
Our global society has started to destroy species of other organisms at an accelerating rate, initiating a mass extinction episode unparalleled for 65 million years (Ceballos et al., 2017).
Climate change will become an increasingly dominant problem in the biodiversity crisis, but human development and population growth mean that the impacts of overexploitation and agricultural expansion will also increase (Maxwell et al., 2016).
The human consumption of animal foods is one of the most powerful negative forces affecting the conservation of terrestrial ecosystems and biological diversity. Livestock production is the single largest driver of habitat loss and both livestock and feed crop production are increasing in developing tropical countries, where the majority of biological diversity resides (Machovina et al., 2015).
The loss of biological diversity is one of the most severe human-caused global environmental problems (Ceballos et al., 2017).
Scientists say that an exceptionally rapid loss of biodiversity over the last few centuries indicates that a sixth mass extinction is already under way. “Averting a dramatic decay of biodiversity and the subsequent loss of ecosystem services is still possible through intensified conservation efforts, but that window of opportunity is rapidly closing” (Ceballos et al., 2015).
Human consumption of animal foods inevitably impacts the environment, but there is much scope for increasing global food availability in such a way that halts impacts on biodiversity. The devastating impact livestock farming is having on the world’s rich biodiversity can be stopped through the widespread adoption of a vegan diet.
“A vegan diet is probably the single biggest way to reduce your impact on planet Earth, not just greenhouse gases, but global acidification, eutrophication, land use and water use” says Joseph Poore, researcher at the University of Oxford (Carrington, 2018).
We know biodiversity loss affects ecosystem function, but how it does is not entirely clear, we are gambling with very high stakes. Ignoring the devastating impact livestock farming is having on biodiversity has been likened by some scientists to playing a game of ecological roulette. Government support for a radical change in recommended diets is long-overdue and the need for action has never been so urgent.