What's the Earth's biggest threat to biodiversity?

By: Jonathan Atteberry  | 
Slash and burn deforestation in the Amazon Basin circa June 2001.
Marcus Lyon/Getty Images

Earth is a planet teeming with life, boasting an incredible array of species. While we've already identified nearly 2 million individual species, it's estimated that over 9 million more are yet to be discovered. This vast biodiversity is not just a subject of academic interest; it's essential for human existence. That's why there's concern about threats to biodiversity.

Take, for example, the role of microorganisms like worms and bacteria in breaking down organic waste and enriching the soil with nitrogen — a process crucial to modern agriculture. Furthermore, pharmaceutical companies rely on a diverse range of plants and animals to synthesize medications, and we can only speculate about the untapped medicinal potential within Earth's undiscovered species.


But the significance of biodiversity extends beyond agriculture and medicine. Earth's plant life plays a vital role in mitigating global warming by absorbing carbon dioxide. Astonishingly, nearly 90 percent of these plants, including about two-thirds of our food crops, depend on approximately 190,000 species of pollinating insects. In fact, when we quantify the value of services provided by Earth's plants and animals, considering everything from ecotourism to biological pest control, the total reaches a staggering $2.9 trillion.

Climate Change and Invasive Species: A Threat to Biodiversity

Clearly, the planet would be a vastly different place without its rich and diverse ecosystems. However, there are looming threats to biodiversity that we must address. For instance, the changing climate and the introduction of alien species are both a core threat contributing to species extinctions.

Global climate change is pushing many species out of their habitats as they seek more suitable temperatures, and the risk of extinction for some species is a grim reality. Overhunting, as seen in the tragic extinction of the passenger pigeon, continues to jeopardize animals like the rhinoceros. Additionally, the introduction of alien species, such as kudzu and the brown tree snake, by human activities can rapidly drive native species to extinction. In the United States alone, invasive species cause annual economic damage estimated at between $125 and $140 billion.


Loss of Biodiversity: A Global Crisis

The loss of biodiversity is a global crisis that demands our attention. Earth's rich and diverse ecosystems are under constant threat. Perhaps the greatest of all threats to Earth's biodiversity is deforestation. While deforestation poses a threat to ecosystems worldwide, it's especially devastating for tropical rainforests. These rainforests, despite covering only 7 percent of the Earth's surface, host over half of the world's species.

The consequences of deforestation are dire. Through activities like logging, mining, and intensive farming, we destroy more of the Earth's rainforests annually, often causing irreparable damage to the soil in the process. As these habitats disappear, plants and animals are forced into fierce competition for the remaining space, with those unable to adapt facing extinction. In recent history, deforestation has been responsible for approximately 50,000 extinctions a year, a number that is expected to rise as habitat loss accelerates.


Human Population Requires Resources

As the human population requires more resources to sustain itself, the demand for land and resources often leads to habitat destruction. This increasing pressure on ecosystems further exacerbates the loss of biodiversity. The need for food, housing, and other essentials has led to the conversion of natural habitats into agricultural fields, urban areas, and industrial zones. These activities not only reduce the available space for wildlife but also contribute to pollution and fragmentation of habitats.


Extracting Natural Resources

Balancing the use of natural resources with the need to protect biodiversity is a complex challenge. Human societies depend on natural resources for their survival and development, but the excessive exploitation of these resources can have detrimental effects on ecosystems. Deforestation, overfishing, and the extraction of minerals are just a few examples of activities that can harm biodiversity.

Unsustainable resource extraction is a leading cause of biodiversity decline. When natural resources are extracted in an unsustainable manner, it often results in habitat destruction and the disruption of ecosystems. This not only harms wildlife directly but also has cascading effects on the entire ecosystem. Finding ways to extract and utilize resources more sustainably is a critical step in mitigating the impact on biodiversity.


Air Pollution

Air pollution can have detrimental effects on both terrestrial and aquatic species. The release of pollutants into the atmosphere, including chemicals and particulate matter, can lead to acid rain, smog, and other forms of pollution that can harm ecosystems. For example, acid rain can lower the pH of bodies of water, making them uninhabitable for certain species of aquatic life. Smog and air pollutants can harm the respiratory systems of terrestrial animals, including birds and mammals, leading to population declines.


Deforestation: A Grave Threat to Biodiversity

Deforestation, as mentioned, is one of the major threats to biodiversity worldwide. While irresponsible logging and mining practices are often blamed, they are symptoms of larger issues. Many rainforests are situated in developing countries with limited resources for enforcing environmental regulations. These countries also benefit economically from the activities of these companies, providing little incentive to discourage deforestation. Furthermore, indigenous populations, whose livelihoods depend on the rainforest's resources, often clear land for agriculture and cattle ranching, making it challenging to curb this activity without affecting their well-being.


Stopping Biodiversity Loss

Nonetheless, there is hope for Earth's rainforests. In Brazil, stricter environmental regulations and enhanced enforcement have contributed to a significant decrease in deforestation rates, as revealed by satellite imagery. Research also indicates that as a country's economic conditions improve, its rate of deforestation decreases, as indigenous populations become less reliant on rainforest resources for survival.

Moreover, nonprofit organizations like the World Wildlife Fund and the Sierra Club continue to raise awareness about the vital importance of Earth's rainforests. One such nonprofit, the Nature Conservancy, collaborates with local Brazilian municipalities to assist landowners in registering their rainforest plots, promoting accountability to Brazil's environmental regulations. Through collective conservation actions involving governments, nonprofits, and indigenous communities, we may yet halt the destruction of these invaluable ecosystems before it's too late.


This article was updated in conjunction with AI technology, then fact-checked and edited by a HowStuffWorks editor.


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