Wildfires are on the rise in recent years, and they’re often deadly. Climate change caused by humansYou can also find out more about the following: Disruptive land management practices. Southern California is where we all live and have our jobs. Hit especially hard.
Southern California was also hit by a wildfire wave 13,000 ago. These fires permanently changed the vegetation in the region. The largest mass extinction on Earth was caused by the human raceMore than 60 million years ago.
You may also like paleontologists, You can find out more about us hereA unique perspectiveOn the long-term causes of and consequences of environmental change, including those caused by human activity and those due to climate fluctuations.
A new study has revealed some interesting factsIn August 2023 we published a report to try and understand what was happening in California when the last major extinction occurred. The Pleistocene endedThis time period is called the Ice Age. This event was responsible for the extinction of a large number of species. The majority of Earth’s mammals are large mammalsIt was between 10,000 and 50.000 years ago. This period was marked by climate change and a rapid expansion of human populations.
The last major extinction
Scientists refer to the last 66,000,000 years of Earth’s evolution as the Age of Mammals. Our furry relatives took full advantage of the environment during this time. extinction of dinosaursTo become the dominant animal species on the planet.
During Pleistocene times, Eurasia and Americas were home to enormous beasts such as woolly mammoths. giant bears. and dire wolves. Two species of camels as well as three ground sloth species and five large cat species were found in Eurasia and the Americas during the Pleistocene. Los Angeles, as it is known today, was once roamed by a group of people..
They were suddenly gone. The large mammals which had dominated global ecosystems over tens and millions of years vanished from all corners of the globe. North America More than 70% of the population has lost weightMammals weighing over 97 lbs (44 kg). South America lost nearly 90%, Australia more than 80%. Africa, Antarctica, and a few isolated islands are the only places that still have “natural” animal populations.
The cause for these extinctions has not been determined. Paleontologists and archaeologists debated possible causes for decades. Scientists have been baffled by the fact that there is a multitude of possible causes, not because there are none.
Climate change caused weather patterns to be altered and the organization of the earth changed. plant communities. At the same, human populations increased rapidly. Spreading around the world.
These processes can be either or both involved in an extinction. It is difficult to tell when large mammals disappeared from a specific region because the fossil record for that area is typically sparse. This makes it hard to tell if habitat destruction, resource scarcity and natural disasters or human hunting are the culprits.
A deadly combination
Some records contain clues. La Brea Tar PitsIn Los Angeles, the richest Ice Age fossil site in the world, thousands of large mammal bones were preserved by asphalt seeps. Over the last 60,000 years. The proteins found in these bones are dated with precision Using radioactive carbon, giving scientists unprecedented insight into an ancient ecosystem and an opportunity to illuminate the timing – and causes – of its collapse.
This study was conducted at the La Brea Tar Pits. Near Lake ElsinoreA dramatic event that occurred 13,000 years ago permanently altered the vegetation of Southern California. Causes of disappearanceLa Brea’s iconic Mega-Mammals
Sediment archives from the lake’s bottom and archaeological records provide evidence of a deadly combination – a warming climate Droughts lasting decades are a constant featureHuman populations are growing rapidly. These factors have pushed Southern California’s ecosystem to the tipping point.
Similar combinationsOther studies have blamed climate warming and human impact for extinctions during the ice age, but our research found something different. A dramatic increase in the number of wildfires likely caused by humans is thought to be responsible for this dramatic change.
Today, we are familiar with the processes which led to this collapse. California’s landscape became drier as it emerged from the last ice ages. Forests also began to recede. In La Brea, the herbivore population declined. This was probably due to a combination between human hunting and habitat destruction. Tree-associated species like camels disappeared.
The average annual temperature in the area during the millennium preceding the extinction was averaging 20°C. rose 10 degrees FarenheitThe lake started to evaporate at (5.5 degrees Celsius). After 13,200 years the ecosystem experienced a 200-year drought. The remaining half of trees died. As there were fewer large herbivores around to eat the vegetation, it accumulated on the landscape.
During this time, the human population began to expand across North America. And as they spread, people brought with them a powerful new tool – fire.
Our ancestors and we humans have used fire to create a variety of products. The Earth has been around for hundreds of thousands or even millions of yearsBut fire has different impacts in different ecosystems. Lake Elsinore charcoal records reveal that, before humans arrived in Southern California, fire activity along the coast was minimal. As human populations increased in the region 13,200-13,000 years ago fires increased by an order-of magnitude.
Our research indicates that the combination heat, drought, loss of herbivores and human-setfires has pushed this system into a Tipping point. After the fires, Southern California was covered with chaparral, a plant that thrives after a fire. A new fire regime was established and the iconic La Brea giant fauna had disappeared.
Future lessons
The Pleistocene extinctions can help us understand the current climate and biodiversity crisis. The extinction of the Southern California ice ages was a result of a similar combination climate warming, human population growth, biodiversity loss, and fires caused by humans. Playing out again today.
Today, temperatures are rising at alarming rates. Ten times fasterThis is primarily due to the burning fossil fuels. The human-caused Climate ChangeThe California state has seen a fivefold increase of fire intensity, frequency and area burned. Past 45 Years.
California has now Famous for extreme firesOur study shows that fires are a relatively recent phenomenon in the region. Lake Elsinore’s record of fires shows that they were very rare in the 20,000 years preceding the extinction. This was true even when there were similar periods of drought. Fire is only a part of the ecosystem after humans arrive.
Even today Downed power linesCampfires are a great way to enjoy the outdoors. Other human activitiesStart here Over 90%Wildfires on the California coast.
The parallels between today’s environmental crisis and the megafaunal extinctions of the Pleistocene are striking. Past experience has taught us that our ecosystems can collapse under pressure from multiple interlocking factors. Redoubling our efforts to reduce greenhouse gas emissions, stop reckless fires from igniting and protect Earth’s megafauna will help us avoid another, more devastating transformation.
Emily LindseyAssociate Curator at the La Brea Tar Pits, Adjunct Professor, Institute of the Environment and Sustainability (UCLA) University of California Los Angeles; Lisa N. Martinez, Ph.D. Candidate of Geography University of California Los Angeles. Regan E. DunnAdjunct Professor in Earth Sciences USC Dornsife College of Letters, Arts and Sciences
This article has been republished by The ConversationUnder a Creative Commons License. Read the Original Article.
