Are we approaching extinction?

Have you ever had that unsettling sense that you might not have much time left? You could be onto something. A recent study suggests that Earth could be on the brink of a catastrophic mass extinction.

Population ecologists are experts who investigate the connection between species and their environments. In research conducted at the Universities of York and Leeds in Great Britain, these specialists examined the fossil record and uncovered alarming findings. It seems we are living in a climate that has historically led to the extinction of numerous species. So, what does this mean for humans?

Earth's History of Biodiversity

The fossil record chronicles the Earth's history, drawn from fossils, rock strata, ice cores, and various geological events. These pieces of evidence collectively create a detailed narrative of life and climate on Earth over the last 550 million years.

A study by population ecologists compared 520 million years of Earth's climate shifts with species extinctions over the same period. Their findings raise concern: during cooler 'icehouse periods,' biodiversity flourishes. Biodiversity refers to the wide variety of species present. In ecosystems rich in diversity, conditions are favorable for evolution, reproduction, and genetic divergence. In essence, if the planet were a business, biodiversity would be a sign of its prosperity.

However, in warmer 'greenhouse periods,' biodiversity declines. This reduction in biodiversity is primarily attributed to mass extinctions—events where numerous species vanish. The study by British population ecologists reveals that as global temperatures have risen in the past, extensive species loss has occurred. Could the impact of past climate-driven mass extinctions provide a glimpse into our future?

The Sixth Mass Extinction is Coming

Why is this important to us? Some of the most severe mass extinctions in Earth's history took place during climates remarkably similar to today's. Researchers from York and Leeds predict that, with anticipated temperature increases this century, Earth could experience another mass extinction event within just a few generations. This means that the grandchildren of today's young readers could witness the next mass extinction.

Science cannot definitively state that a mass extinction will occur. There is no direct proof linking periods of global warming to past extinction events. However, researchers have found strong correlations between global warming and mass extinctions throughout history. These warmer periods consistently coincide with times of significant species loss.

The most catastrophic mass extinction in Earth's history occurred 251 million years ago, at the close of the Permian Period, marking the end of the Paleozoic Era. During this event, 95 percent of all life on Earth vanished [source: University of York]. The exact cause remains unclear, but some scientists suggest a series of comets struck Earth, causing the oceans to acidify (also triggering acid rain). Others believe the eruption of volcanoes released toxic gases that led to the same catastrophic acidification. Regardless of the cause, it's evident that these disasters were accompanied by a rise in global temperatures.

Is the Human Race Up to the Challenge?

But why should we worry about the possibility of another mass extinction like the one at the end of the Permian Period? After all, we've already overcome issues like acid rain. Plus, if it gets too hot, we have air conditioning to stay cool. Surely, both we and our pets will be fine, even if mass extinction happens—right? Probably not. The reality is that the extinction of 95 percent of species would have devastating consequences for the remaining 5 percent.

Humans have made remarkable progress in gaining control over the forces of nature. We have learned to build shelters, clothe ourselves, and grow food through agriculture and irrigation. We’ve created schools, hospitals, computers, automobiles, airplanes, and space shuttles. So why should we care if a large number of plants, animals, and simple organisms disappear?

Human Beings Need Other Species for Survival

The issue with losing biodiversity is this: The Earth operates like an intricate machine, and there doesn't seem to be any unnecessary parts. Every species, from the smallest microbe to humans, contributes to maintaining the balance of the planet. In this regard, all parts are interconnected. If a significant number of these parts were to disappear, the machinery of Earth would begin to falter.

For instance, the crops we cultivate through advanced agricultural practices rely on the nitrogen in the soil. This nitrogen nurtures and strengthens our crops. But where does it come from? Worms, bacteria, and other soil-dwelling organisms thrive on decomposing plant matter. As they feed, these organisms release nitrogen as waste, which plants love. This is also how nutrient-rich compost is formed. If these bacteria species were wiped out, our crops would suffer, and food would become scarce.

This principle extends to ocean ecosystems as well. The ocean, along with land-based plant life, plays a crucial role in absorbing carbon dioxide, a gas that is not breathable for humans. However, the ocean cannot absorb this CO2 on its own. It depends on organisms like phytoplankton, tiny aquatic plants, to absorb the CO2. Without phytoplankton, we lose a vital source of breathable air.

A Dire Threat to the Survival of Humanity

Some of our greatest technological breakthroughs actually depend on nature. For instance, modern medicine is deeply rooted in the natural world. Many essential medications, such as painkillers, penicillin, and vaccines, are derived from plants and bacteria. While some of these medications are synthetic versions, others, like antibiotics, still rely on the living organisms themselves. If biodiversity were to suddenly vanish from Earth, it would not only affect the medications we currently use but also the ones yet to be discovered.

Even if humanity could adapt to a world without biodiversity, it would undoubtedly transform our existence. The economic value of biodiversity is substantial. In 1997, researchers at Cornell University calculated that the services provided by nature to humanity—such as pollination, soil formation, and pharmaceuticals—were worth $2.9 trillion annually (with some studies estimating the value at $33 trillion). These invaluable contributions are the foundation of much of our survival and prosperity.

These essential services would remain necessary, regardless of the state of Earth's ecosystems. As resources like nitrogen—created by worms—diminish, humans would need to step in to replace them. The demand for things such as nitrogen for crops or medicine for the sick would skyrocket. This competition for limited resources would intensify, favoring wealthier, more powerful nations. The loss of biodiversity would worsen life for humanity, leading to greater inequality and hardship.

The Growing Risk of Human Extinction

The human species is currently facing unprecedented existential threats. While the dangers of a climate crisis have always loomed, early humans never had to deal with the threat of nuclear weapons or the widespread pollution caused by human activity.

If humanity is to survive for more than just the next century, we must make significant sacrifices to combat climate change. Without urgent action, we risk ecological collapse and a mass extinction event unlike anything the human race has encountered in millions of years.

For additional insights into earth sciences, make sure to visit the next page for more detailed information.