The Cenozoic Era is divided into two epochs known as the Pleistocene and the Holocene . The Holocene is the most recent epoch, as it is the one in which our planet currently finds itself. It began approximately 12.000 years ago, specifically in 10.000 BCE, and continues to this day. This period encompasses most of human development, from the emergence of Homo sapiens to the technologies we have today.
In this article we are going to tell you everything you need to know about the Holocene epoch.
General characteristics
During this period, the planet has changed very little. Most of the changes observed are in biodiversity, as modern human activity is causing the extinction of thousands of plant and animal species. Humans have become the dominant species on the planet despite causing it immense harm.
The Holocene epoch spans approximately 12.000 years and encompasses all of human development, including the establishment of the first social groups and the first human civilizations. It also saw significant cultural, intellectual, and technological advancements that enabled the development of diverse cultures, as discussed in the article on the Indus Valley Civilization . Furthermore, the extinction of many species, linked to human activity, is a topic that warrants attention, as detailed in the article "Humans Causing Extinctions ."
During this era, there has been a mass extinction of species, observed throughout a continuous and ongoing process. These species, both animal and plant, have been greatly reduced due to human action. This entire process has been classified by specialists as one of the most serious extinctions ever to occur on our planet. This is because the cause of extinction was not due to environmental factors but to one of the species inhabiting the planet, which has become the dominant one.
The Holocene is considered to have been an interglacial period . This is a time when intense cooling ends and less ice cover is found. It is expected that another glaciation will occur in the not-too-distant future, as current studies and knowledge from the fossil record indicate that another ice age is imminent. Therefore, it is important to study climate changes throughout history, such as the next glaciation in Spain and climate change at Cape Horn.
Holocene Geology
Geologically, this period has been relatively uneventful, with no major changes in orogenic movements or continental configuration . Some fragments of the supercontinent Pangaea have continued to drift, but at a much slower pace than in ancient times. The continents have moved a mere kilometer since the beginning of this period. However, it's important to note that continental landmasses will never cease moving, and it is expected that in a few million years they will collide again and form another supercontinent.
During this period, sea levels have also risen due to glacial melt. Many of the lands now submerged were once land bridges connecting regions. In this sense, the melting has not been a gradual process; rather, there have been periods when the melting reached peak levels, causing a more abrupt rise in sea level . This is crucial for understanding how glaciation has influenced the planet and how Holocene fauna may have been affected.
Considering these data, we can conclude that sea level has risen a total of 35 meters since the beginning of the Holocene. A worrying fact is that over the last 25 years, sea level has risen again at a rate of approximately 3 mm per year, which is somewhat accelerated compared to the normal rate. This is due to an increase in the greenhouse effect, which is causing a rise in global temperatures and is caused by the action of some of the gases that are capable of retaining heat.
Holocene climate
Temperatures during this period are considerably milder than in previous periods. This is because it is an interglacial period. Average temperatures increased by approximately 4 to 9 degrees Celsius. Global warming was uneven, with some regions experiencing greater increases and others experiencing a decrease. The lands that experienced the greatest cooling were those located further south.
In other regions that have historically had a desert climate, rainfall began to increase, demonstrating how the climate has been changing throughout the Holocene. This climate change is reflected in the fauna and flora adapting to new conditions, as detailed in the Holocene fauna section.
Flora and fauna
The evolution of life during the Holocene epoch has not undergone significant changes from an evolutionary perspective. The most notable trend observed during this period is that species have begun to disappear at an unprecedented rate. Many attribute this decline in species numbers to the emergence of humankind, as evidenced by mass extinctions . This extinction trend continues to the present day, with a large number of species currently facing extinction.
Angiosperms are the most widely distributed plants on the planet. The tropical regions closest to the Equator are home to the largest number of rainforests, which boast abundant plant life and high biodiversity. In areas closer to the poles, the vegetation changes dramatically. The lush, humid rainforests give way to other types of trees adapted to cooler temperatures.
As for fauna, animals haven't changed much during the Holocene. The species that have managed to survive throughout this time have barely undergone any changes or evolution. What has intensified and prolonged is the extinction of both terrestrial and marine animals. All of this is caused by human activity and our desire to conquer the planet, as can be seen in the impact it has on the ecological balance.
