Are We On the Brink of the Earth’s Sixth Major Extinction?

If you could journey back 65 million years, you would witness the fifth mass extinction event on Earth, likely caused by a comet or massive meteor impact that wiped out more than half of all life. Among the lost creatures were the dinosaurs [source: Choi].

As catastrophic as that extinction was, a far larger event occurred 250 million years ago. The Permian extinction eliminated 95 percent of marine species and almost all land life. Scientists attribute this disaster to massive volcanic eruptions in what is now Asia [source: PBS].

Earth may be on the brink of its next mass extinction. A global report published by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) on May 6, 2019, reveals that approximately 1 million species are at risk of disappearing — the highest number in human history.

What is causing such widespread extinction? While there are several contributing factors, human activity appears to be the primary driver. Whether through hunting, habitat destruction, or the introduction of invasive species, humans have greatly affected life on Earth. Our influence dates back 100,000 years, when humans began migrating out of Africa, and accelerated around 10,000 years ago with the advent of agriculture. Since then, human actions have led to the extinction of thousands of species, with 75 percent of terrestrial habitats and 66 percent of marine environments significantly altered, according to the report.

Climate change has also sped up extinction processes, as many plants and animals cannot adapt to changing temperatures. If this trend persists, we may face a mass extinction that could even threaten human survival. More details on this will follow in the next section.

Warning Signs of Extinction

It can be hard to comprehend how the loss of a seemingly minor species could ripple across the entire planet. However, it’s true that the extinction of even one life form can trigger widespread problems for all life on Earth.

Let’s imagine a hypothetical scenario. Picture a lake brimming with life—fish and amphibians swim in the waters, insects live around it, and reptiles, birds, and mammals rely on it for survival. Now, picture the extinction of a single species of insect in that ecosystem. The consequences of this loss could be devastating.

First, any other species that fed on the now-extinct insect—whether other insects, fish, or amphibians—would be affected. These creatures would need to adapt by finding new sources of food, or they could face extinction themselves. Moving up the food chain, predators that relied on these animals would experience a drop in their food supply.

Now, imagine this chain of events occurring worldwide, affecting various levels of the food chain. As Richard Leakey and Roger Lewin highlight in their book "The Sixth Extinction," we could lose up to half of all species on Earth by the year 2100. They emphasize that species extinction can occur even if we halt harmful human practices. Small populations may fall victim to sudden events like natural disasters or disease. However, if we continue to destroy rainforests, the situation will become even more dire.

What can we do to make a difference? It will take sacrifices from us all. A good first step is to reduce our carbon footprint. Cutting down on meat consumption can also be helpful, as livestock farming requires land to be cleared. Reducing harmful practices could help preserve thousands of species over the coming decades—and may even safeguard our own future. The global report emphasizes that the years 2019-2021 are a critical period for addressing climate change and the sixth mass extinction. It urges nations to commit to altering how we feed ourselves and protect nature to curb biodiversity loss and combat climate change.