The question of how many animal species humans have driven to extinction is both complex and deeply troubling. Despite extensive research, the true scale of the damage we’ve inflicted on the natural world remains elusive, though estimates suggest the toll could be in the hundreds of thousands.
The Unseen Impact of Human Activity on Wildlife
Human activities have been devastating to countless Animal Species, leading to the extinction of creatures like the dodo, the golden toad, and the Tasmanian tiger. But just how many species have been lost? The answer isn’t straightforward. Since the beginning of the modern era in 1500, the International Union for Conservation of Nature (IUCN) has recorded 777 animal extinctions. While some of these extinctions may have occurred naturally, it’s highly likely that human influence played a role in nearly all of them, especially given the significant environmental changes we’ve caused over the last 500 years.
However, the 777 figure is just the tip of the iceberg. The IUCN has assessed only about 5% of the world’s known species, indicating that many more extinctions have likely gone unrecorded. A 2022 study published in Biological Reviews estimated that as many as 150,000 to 260,000 species might have perished since 1500. The study’s lead author, Robert Cowie, a research professor at the University of Hawaii, found the numbers so staggering that he initially doubted his own calculations.
Estimating the Unknowable Animal Species
Cowie’s team based their estimate on a detailed analysis of 200 land snail species, determining the extinction rate for these snails and extrapolating it to other species. Their findings suggested an extinction rate of 150 to 260 extinctions per million species-years (E/MSY). When applied to the approximately 2 million known species, this rate implies that 100,000 species have disappeared over the past 500 years.
But the actual number could be far higher. A 2011 study estimated that there are around 7.7 million animal species on Earth. If we apply Cowie’s extinction rate to this larger number, subtracting natural extinctions, the total number of species lost due to human activity could reach 381,150.
The Challenge of Measuring Extinction
Despite these alarming figures, some scientists caution against relying too heavily on current estimates. John Alroy, an associate professor at Macquarie University in Australia, argues that accurately calculating modern extinction rates is nearly impossible given the vast unknowns. Many species, particularly those in understudied regions like the tropics, have yet to be discovered, and our knowledge of certain groups, like insects, remains limited.
Alroy suggests that a more accurate estimate could be achieved by analyzing museum data from specific Animal Species and tracking changes over time. However, even with these challenges, one thing is clear: human activity has dramatically accelerated the extinction rate far beyond the natural background level.
Conclusion: A Dire Warning for Earth’s Biodiversity
Whether the extinction rate is 100 E/MSY, 20 E/MSY, or 200 E/MSY, the reality remains that humans are pushing Earth’s biodiversity to the brink. The number of extinctions is undoubtedly much higher than the 777 recorded on the IUCN Red List, and the consequences of this loss are profound. As we continue to impact the planet and Animal Species, it’s crucial to recognize the irreversible damage being done and take meaningful action to preserve what remains of our natural world.
