Holocene Extinction

The Holocene Epoch, formerly known as the Recent Epoch, is the more recent of the two officially recognized epochs that make up the Quaternary Period. It roughly corresponds to the last 11,700 years of Earth's history. The Holocene is unique because it corresponds with the late and post-Stone Age history of humanity. The sediments of the Holocene, both continental and marine, span the biggest area of the world of any period in the geologic record. A unique geologic name for this period seems suitable given that human influence is so widespread and extensive.

History

Charles Lyell proposed the term "recent" in 1833 to describe the time since "the world has been tenanted by man." We now know that humans have existed for a far longer time. Informally introduced to the International Geological Congress in Bologna, Italy, in 1885, the word "Holocene" was first proposed in 1867. The U.S. Commission on Stratigraphic Nomenclature formally approved it in 1969.

Holocene Extinction

Holocene extinction refers to the ongoing loss of Earth's flora and wildlife because of human activity. Since Earth's creation 450 million years ago, there have been six major extinction events.

Holocene Mass Extinction

The pressure from the human population has had major impacts on the planet's biodiversity. At least five significant mass extinction events have occurred on Earth times when at least 60 percent of extant genera became extinct within a span of no more than a few hundred thousand years. They are:

• Ordovician-Silurian mass extinction (443 million years ago)

• Late Devonian mass extinction (374 million years ago)

• Permian-Triassic mass extinction (251 million years ago)

• Triassic-Jurassic mass extinction (201 million years ago)

• Cretaceous-Paleogene mass extinction (66 million years ago)

Many scientists think we are currently experiencing the sixth human-caused major extinction catastrophe. Up to 30% of plant and animal species may go extinct within the next 100 years, according to estimates based on population sizes needed to sustain genetic viability. The primary reason for species extinction in the modern era is habitat deterioration.

Earth’s Sixth Mass Extinction

The sixth global extinction event on Earth is happening right now, and it is escalating. The Holocene extinction, which started at the end of the last ice age, has been going on for the past 10,000 years. But the threat posed by this mass extinction has only grown due to an expanding human population and a warming world. The vast majority of "vertebrate extinctions experienced in the 20th century" are predicted to occur again, according to Science Alert. For instance, it is believed that humanity lost "at least 543 terrestrial vertebrate species" to extinction in the 20th century. Within the next 20 years or so, according to the study's authors, we stand to lose roughly the same number of species.

The bees are required to continue pollinating our food crops, such as broccoli, melons, apples, blueberries, and cranberries. California's $11 billion almond sector is likewise reliant on honey and bumble bees. Farmers hire apiarists to send bee colonies to their fields to pollinate fruits, vegetables, and nuts because bees are such useful and efficient pollinators. In fact, bumble bees are nearly entirely responsible for most of the tomato pollination and, in certain situations, outperform honeybees in this regard. This is because they can use a technique called buzz pollination or sonication to extract pollen that is firmly bonded to the host plant.

The fate of millions of species will depend on how we respond to the current extinction crisis over the next two decades, according to Gerardo Ceballos, an ecologist, and researcher at the National Autonomous University of Mexico and the lead author of a recent study published in the Proceedings of the National Academy of Sciences (PNAS).

The Holocene "may be the most serious environmental threat to the persistence of civilization, because it is irreversible," according to Ceballos and two co-authors of t. They go on to say that "consumption rates" and the fast-expanding human population are two of the main reasons for extinction. Because species are interconnected components of ecosystems, when one disappears, the others are likely to follow. Regional biodiversity collapses are probably happening in areas where losing species are concentrated.

Around 94% of the populations of 77 mammal and bird species that were on the verge of extinction, according to Ceballos and team, had been lost in the past century. More than 237,000 populations of those species have disappeared since 1900 if all species on the verge of extinction exhibit similar tendencies.

Interesting Facts

• The Holocene extinction is the sixth mass extinction event in Earth's 4.5-billion-year history

• Fossils are the only evidence of mass extinction.

Important Questions

1. What are the greatest challenges in paleoclimatology?

Ans: The fact that many commenters on climate change are selective with their data poses one of the biggest problems for paleoclimatology. Where it contradicts the prevailing wisdom, it is merely written off as an aberration, but where it concurs, it is an undeniable fact.

2. What connection exists between the lagoon sedimentation rate and the atoll coral growth rate close to sea level?

Ans: A lagoon is a body of water that is surrounded by an atoll. Lagoons and atolls can occasionally shield a main island. Lagoons are linked to the open ocean or sea through channels that run between islets.

3. How can the paleoclimate of two distinct places be compared over a certain period of time?

Ans: The study of earlier climates is called paleoclimatology. Since it is not possible to travel back in time to see former climates, scientists utilize proxies—imprints left by previous climates—to interpret paleoclimate. Diatoms, forams, and coral are a few examples of organisms that are good climate proxies.

Key Features

• The word "Holocene" was first proposed in 1867

• Holocene extinction refers to the ongoing loss of Earth's flora and wildlife because of human activity

• Five significant mass extinction events have occurred on Earth

• Holocene extinction, which started at the end of the last ice age, has been going on for the past 10,000 years.