As animal agriculture expanded, the population of farm animals on Earth exploded. So, have we done a favour for the animal kingdom as a whole if we increase the population of these animals? What about wild animals? Does the way in which we raise farm animals affect other species, including us? Let’s find out.
Summary
- The mass of farm animals far outweighs the mass of wild animals on Earth.
- Animal agriculture consumes a lot of land and leads to extensive deforestation, which destroys habitats and hence reduces biodiversity and wild animal populations.
- We reap many benefits from ecosystem services and we must protect biodiversity in order to maintain them.
- Consuming fewer animal products significantly reduces the impact of our diet on biodiversity.
What is biodiversity?
When it comes to investing in the stock market, what is the best long-term strategy? Is it better to invest all of your money into one company, or is it wiser to diversify and invest in many different companies? By simultaneously investing in multiple companies, we will receive an average of the profits from these companies. If one company fails, it won’t significantly impact our investment. This approach greatly reduces risk. In general, systems with high diversity are often more resilient to external stimuli. Similarly, ecosystems with high diversity of species typically respond better to threats. Different species play a variety of important roles within an ecosystem. A highly biodiverse ecosystem may not be greatly affected if one species is lost. For example, biodiverse ecosystems may adapt better to climate change.1 On the other hand, ecosystems with low biodiversity are less adaptable and may lose critical functions when a species is lost.
The sixth mass extinction
A mass extinction is the rapid loss of a large number of species within a short period of time. In the past, there have been five major mass extinction events. These extinctions were caused by natural phenomena such as volcanic eruptions and asteroid impacts. It appears we are currently in the midst of the sixth mass extinction, but this time, humans are the driving force behind it. The current extinction rate is up to 100 times higher than the average background rate of extinction. Because we are rapidly changing the environment, species cannot adapt and evolve quickly enough. In parallel, the population of species are greatly decreasing and species are becoming extinct.2-4
How does animal agriculture cause habitat loss?
Unfortunately, as animal agriculture expands, it significantly reduces biodiversity. Currently, the combined weight of humans and farm animals is 24 times greater than that of wild animals. Furthermore, 60% of mammals are farm animals.5 The Earth has become a farm.
The livestock industry is a major driver of habitat destruction and is one of the leading drivers of reduced biodiversity. In particular, animal agriculture has negatively impacted the populations of apex predators and large herbivores.6 Most of the worlds biodiversity is contained within tropical developing countries, however, this is also where agriculture is expanding the fastest. Additionally, the effects of climate change are expected to occur earlier in tropical regions.7 The more we expand animal agriculture, the more we deforest and replace natural habitat with grazing lands and croplands for growing animal feed, reducing biodiversity. In contrast, using less land would lead to greater biodiversity.6
One study examined 19,859 species of wild animals and concluded that due to agricultural expansion, 88% of these species will lose habitat by 2050. 1,280 species are projected to lose 25% of their habitats by 2050 due to agricultural expansion. The most severe habitat loss is estimated to occur in Africa, Central America, and South America. However, by adopting a plant-centric diet, reducing waste, optimising land use, and increasing crop yields, we can potentially limit habitat loss to just 1%.8 The less we eat animal products, the less animal agriculture will expand in biodiversity rich regions like the tropics.9
Between 73-83% of endangered birds and mammals are threatened due to the habitat loss caused by agricultural expansion. In particular, larger wild animals face a higher risk of extinction. Logging, urbanisation, hunting, and invasive species also pose threats, but they have a less severe impact compared to agriculture.10 Similarly, in the next few decades, 40% of insect species could face extinction. The primary drivers are again habitat loss and agricultural expansion. Pesticides, diseases, pollution, and climate change are also important factors.11 Furthermore, one-third of tree species are endangered, with agricultural expansion being the leading cause.12 So, if this issue arises from agricultural expansion, why specifically blame animal agriculture? As discussed in previous posts, animal-based foods consume more land and lead to more deforestation. The most effective way to enhance biodiversity is to consume less meat. If we reforest or rewild the lands currently used for grazing or for growing animal feed, biodiversity can gradually recover.
Out consumption of animals poses a threat to one quarter of vertebrate species. Among human-induced factors like forest management, constructing infrastructure, pollution, invasive species, mining, and climate change, consuming animals has the most negative impact on biodiversity. This occurs due to direct hunting of wild animals, bycatch during fishing, the purposeful killing of predators to prevent competition with farm animals, the emergence of diseases, and habitat destruction.13 The rising temperatures due to climate change also have a negative impact on biological diversity. Lowering our emissions from animal agriculture could potentially mitigate biodiversity loss, as it can contribute to reducing global warming relatively quickly.
Even if we don’t completely destroy habitats, fragmenting them makes it harder for wild animals to move.10 Some animals can only thrive within a narrow temperature range. So, as the climate changes, animals may need to move to different areas to avoid extinction. However, deforestation makes this migration more difficult, as it separates habitats and reduces the availability of suitable areas for living. This in turn increases the likelihood of animal extinction.7 Furthermore, many species rely on migration for survival. Even if we do not drive mammals to extinction, the genetic diversity of mammalian species may take millions of years to recover.14 With today’s technology, if a species goes extinct, we cannot bring them back. That species will be lost forever.
Do my personal food choices really affect biodiversity?
To answer this, let’s look at a study that examines the effects of actual dietary choices on biodiversity. A study in the UK showed that compared to individuals who consume a predominantly meat-based diet, vegans had a 66% lower impact on biodiversity. This effect was consistent regardless of where or how the food was produced. Vegetarians, due to their consumption of dairy products, had a 36% lower impact on biodiversity compared to those who consume a lot of meat.15 So in short, yes, our individual food choices really matter.
How does biodiversity affect us?
So why should we care about biodiversity? Well, even if we don’t care about wild animals, there are plenty of other reasons to protect biodiversity for our own self interests. Ecosystem services include things like transporting seeds, improving air quality, improving freshwater quality, climate regulation, soil protection, reducing natural disasters, regulating populations of wild species, providing medicines, providing resources, and enhancing our overall well-being.16
Similarly, insects provide many ecosystem services. For example, pollination of food crops, controlling the population of other insects, decomposing organic waste, and recycling nutrients.11 Furthermore, trees assist other plants, animals, and fungi. Therefore, if species of trees become extinct, it would lead to a reduction in biodiversity, leading to negative impacts on human income.12 However, most of these services are on the decline.16 We tend to take these services for granted, but without them, we would definitely complain. Our food, economic development, and health rely on these services. If we want to protect ecosystem services, we need to boost biodiversity, which means consuming fewer animal products.
Conclusion
Our environment is interconnected. While humans sometimes act as if they exist separately from the environment, we cannot thrive in today’s world without nature. Wild animals are not the only victims of biodiversity loss. We too will lose many vital ecosystem services. Animal agriculture, due to its extensive land use and significant contributions to deforestation, destroys habitats, thereby reducing both biodiversity and the population of wild animals. Consuming fewer animal products can significantly reduce the impact of our diets on biodiversity.
References
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