What Causes Extinction & How Can We Prevent Species Extinction?

Photo by Berend Leupen on Unsplash

Many experts believe we are currently experiencing a sixth mass species extinction. Billions of regional and local wild populations have already been lost, and entire species are becoming extinct at a significantly faster rate than has happened at any time during the last million years. The cause of this global biological annihilation? People.

Our food choices are absolutely central to the fate of wildlife. As humans destroy habitats around the world, break down the climate, and hunt and kill wild animals, including in the oceans, wild populations plummet. Our treatment and exploitation of farmed animals for their flesh, skin, milk, eggs, and other by-products drives environmental destruction, and, alongside other agricultural factors, is a huge driver of this loss of wildlife. We must make drastic changes to slow this down.

The wild world has intrinsic value, and we should respect it on that basis alone, as our ancestors undoubtedly did. But there is another reason to change our ways: Humans rely on biodiversity of wildlife and plant life to survive, and the more we drive them to extinction, the closer we push ourselves to the same fate.

What Is Extinction?

Extinction is the complete loss of a species from our planet. Species loss occurs naturally over millions of years, and is a normal part of evolution. There is a natural rate to the frequency of extinctions: around 10 percent species loss every million years; 30 percent every 10 million years; and 65 percent every 100 million years. Evolution is able to occur due to the balance that extinction creates, alongside ‘speciation’—the creation of new species.

Mass extinctions are categorized as periods with unnaturally high extinction rates over a shorter than normal period of time. Previous mass extinctions were likely due to natural climate change events, happening across hundreds of thousands of years, or high-impact events like asteroid strikes. The difference today is that our climate is changing extremely rapidly and species are going extinct at an alarming rate, with many more on the brink. Since 1980, extinction rates have been 165 percent faster than any previous extinction event.

All the evidence points to human activity as the cause.

Types of Extinction

There are two scientific categories of extinction: phyletic and terminal.

• Phyletic Extinction or Pseudoextinction

Phyletic extinction is when a species evolves into another species that is similar, but can no longer be categorized as the same species. This is less impactful, as there is no net loss of species.

• Terminal Extinction

Terminal extinction happens when a species is lost from the Earth completely. Once this happens, there is no natural way this species can return. Terminal extinction is happening frequently around the world, to precious and diverse animal species, which is a huge loss to all living things on the planet.

Why Does Extinction Matter?

The survival of a diverse range of flora and fauna matters when it comes to human and animal survival on this planet. As we have said, we are likely in the midst of a sixth mass extinction event, caused by human activities and if this continues, we risk destroying the life support system that not only we rely on, but also the wild world. And is not just human survival that matters, we should protect the natural world because animals and plants, matter in their own right, not just because we need them for survival.

Human impacts of the natural environment not only destroy the lives of plants and animals but also erode our own wellbeing, social structures, economies, and food security. This is because we are connected to nature, we are more a part of the natural world than we may currently realize, and rely heavily on the ecosystem services the Earth provides.

How Are Humans Causing Animal Extinction?

All signs point to humans as the main cause of the unnatural rates of extinction we are experiencing. According to the world’s leading climate scientists, around 75 percent of land environments have been ‘severely altered’ by human actions, as well as about 66 percent of marine environments.

Animal agriculture is the familiar culprit. More than one-third of the Earth’s available land is now taken up by agriculture and 83 percent of this is for farming animals. It takes the lion’s share of the land but gives us just 18 percent of our calories. This is extremely inefficient but also devastating when it comes to species loss. Growing of feed crops and creating pasture for farmed animals (primarily cows), are the leading causes of deforestation, and deforestation drives species loss. Even though animal agriculture already greedily demands most of our agricultural land, there is always hunger for more, and this continues to be taken from nature.

1. Overfishing

The marine environment is ancient, diverse, and delicate, and the fishing industry disrupts this environment causing massive species loss.

Bycatch, where fishing vessels catch whatever they can, then throw endangered species they are not allowed to catch back into the sea dead or dying, has caused devastating loss of marine life. Bycatch and overfishing has driven over one-third of all shark and ray species towards a global extinction crisis. This is not just an upsetting loss of precious life, but it also risks the collapse of marine ecosystems, a devastating outcome for all life on this planet, including humans. More than 90 European fish species are also threatened with extinction.

2. Deforestation

One third of the planet’s forest, an area twice the size of the US, has been lost to deforestation during human history. Global appetite for meat products means more is lost every day, and the result is massive losses to species that live in these forests.

This is how much we have lost in recent years and the leading causes.

These losses come in some of our most precious and biodiverse tropical forests, which are home to over half of the world’s species. When we cut these forests down, we lose unique species and damage these ecosystems forever.

3. Habitat Loss

Our current food system is hungry for land and again animal agriculture is responsible. Beef and soy production alone are responsible for more than two-thirds of habitat loss in Brazil’s Amazon rainforest, one of the most biodiverse and ecologically crucial ecosystems on the planet. Considering 75 percent of soy is fed to farmed animals, and animal agriculture is responsible for the majority of tropical habitat loss, what we choose to eat is the most important tool we have for bringing this injustice to an end.

4. “Invasive” Species

Sometimes, certain predatory species become dominant in an ecosystem due to a lack of predators for themselves, resulting in other species being wiped out. Many view so-called ‘invasive species’ as the problem, when humans are really at fault. Most species do not “invade”. They are more often captured, relocated, and abandoned in new territories by people.

There are many examples of humans, intentionally or otherwise, introducing invasive species into an ecosystem and the results can be devastating. Burmese Pythons, who are a non-native species but a popular pet in the state of Florida, are often released into the wild when they get too large. With no predators, they prey on local birds, mammals, and even alligators, at an unsustainable rate.

The lesson here is that we should leave nature alone. The majority of the time, human intervention in nature leads to the unnecessary loss and suffering of animal life and an unsustainable imbalance in our ecosystems.

5. Pollution

Pollution, particularly of plastics, has directly contributed to over 700 species worldwide being at risk of extinction. Water birds and mammals are particularly vulnerable, with one study, in one small area, documenting 28 incidents involving seals killed by plastic in 2018 alone, compared to five in 2015.

In the US, there are 494 critically endangered species and scientists predict that 48 of these will suffer further from agricultural pollution, energy pollution, and waste disposal.

6. Climate Breakdown

The outcomes of climate breakdown, including severe weather, rising sea temperatures, changing ecosystems, and increased temperatures all put animal species at risk. According to new data, climate breakdown and the related actions that cause it, are responsible for at least 318 animal extinctions, as well as pushing many more to the brink of extinction.

In the US, 69 percent of the 494 already critically endangered species are predicted to continue to decline due to the adverse effects of climate breakdown.

7. Lack of Genetic Diversity

Humans meddling with genetic diversity, usually to create new agricultural breeds, increases the risk of plant and animal extinction, as it decreases the resilience of species. Habitat loss also greatly reduces genetic diversity, as fewers individuals remain to breed naturally and create genetic diversity. This leaves the remaining species extremely vulnerable to further ecological changes.

So, once again, our best course of action is to leave nature alone as much as we possibly can, and the most effective way we can do this is to change our diet to one that is more plant-based.

8. Lack of Food

When we reduce animals’ natural habitats, kill them, and pull fish out of the sea, we interrupt vital food webs that ecosystems rely on to thrive. If a predatory species does not have enough food, they will die. If they have a predator, that predator will also die, and so on. What will be left is barren, speciesless land and seas. Without the animal species, plant life will also suffer. If we leave them alone however, and eat only plants we can produce sustainably, ecosystems will thrive and extinctions will return to a natural rate.

9. Hunting

Hunting for pleasure is an unnecessary and barbaric act, it also reduces the number of species on the planet. A number of species have already been hunted to extinction and despite stricter laws against illegal poaching, many more remain hunted and endangered.If we stopped hunting wild animals, we would give nature a better chance of regenerating, and allow wild populations to flourish once again.

What Are The Natural Causes Of Extinction?

History has shown that mass extinctions can happen due to a natural event, such as major changes to the Earth’s climate, a widespread disease, or major impact events like asteroid strikes. These natural events either take place over millions of years, or are extremely rare.

1. Asteroid Strikes

There is only one known mass extinction from an asteroid strike and it happened around 65 million years ago. Scientists theorize that the asteroid hit the Yucatan peninsula in Mexico, causing cataclysmic extreme weather events like tsunamis, dust clouds, and fires, resulting in rapid changes to the climate. This event is very likely to have caused the extinction of the dinosaurs.

Events like this show us what happens when a layer of our ecosystem is removed. The change in climate caused plant life to die, which led to herbivores suffering and inevitably carnivores after that, leading to massive extinction worldwide. Our current treatment of our ecosystems will result in similar outcomes if we do not change.

2. Climate Change

Natural climate change, over millions of years, is another cause of extinction. There are a few known examples of mass extinctions caused by changing climates and this change can be caused by intense volcanic or glacial activity. A crucial distinction between this kind of climate change and the changes we are currently experiencing is the rate at which things happen. We are experiencing changes across hundreds of years, whereas previous natural climate change took place over millions.

3. Disease

Research shows that infectious disease is a contributing factor in around four percent of species extinctions that have occurred since the year 1500, as well as contributing to species being critically endangered.

Disease can occur naturally, but again, human-induced habitat loss and climate breakdown only increases the chance of infectious disease leading to species loss. The dirty and disease ridden conditions that animals are forced to endure when farmed also encourages the outbreak of deadly pathogens in farmed animals, which can easily be spread to wildlife, and lead to massive species loss.

4. Better-adapted Competition

Evolution can seem cruel at times, and often, a species will be ‘out-evolved’ by another competing species that simply adapts faster. This happens occasionally and is part of the natural world. The difference with humans is that we have a choice to do the right thing and protect our fellow species, rather than destroy them.

How Can We Prevent Extinction of Species?

There are many factors that lead to the extinction of species but there is one thing we can all do to make a significant impact on preventing further species loss and help pull species back from the brink: go vegan. This is the single most effective thing we can do to prevent extinctions.

Animal agriculture is responsible for the majority of deforestation, habitat loss, and pollution that leads to devastating species losses, and if we continue to eat in the way we do, this will only get worse. By ending the demand for meat, milk and eggs from animals, we end the industry’s insatiable hunger for land and resources that is destroying biodiversity. By going vegan we also stop supporting genetic mutation practices that lead to higher vulnerability for animal species, as well as avoid exploiting animals in ways that can lead to unnatural “invasive” species.

We can also support organizations doing amazing conservation work to bring endangered species back to a healthy, natural level. Here is a list of 35 environmental non-profits worth supporting.


More animal and plant species are becoming critically endangered and going extinct at an alarming and unnatural rate. The consequences of this go beyond just the heartbreaking loss of unique species but also put life on this planet at risk.

We can help slow down and end this injustice by making plant-based food choices and supporting organizations doing the right thing for the millions of unique species on our planet.

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