No species lasts forever — extinction is part of the evolution of life

At least five times, a biological catastrophe has engulfed the planet, killing off the vast majority of species from water and land over a relatively short geological interval.

The most famous of these mass extinction events — when an asteroid slammed into Earth 66 million years ago, dooming the dinosaurs and many other species — is also the most recent. But scientists say it won’t be the last.

Many researchers argue we’re in the middle of a sixth mass extinction, caused not by a city-size space rock but by the overgrowth and transformative behavior of a single species — Homo sapiens. Humans have destroyed habitats and unleashed a climate crisis.

Calculations in a September study published in the journal PNAS have suggested that groups of related animal species are disappearing at a rate 35% times higher than the normally expected rate.

And while every mass extinction has winners and losers, there is no reason to assume that human beings in this case would be among the survivors.

Michael Benton, a professor of vertebrate paleontology at Bristol University in the United Kingdom  is the author of the new book “Extinctions: How Life Survives, Adapts and Evolves.”

Apocalyptic volcanoes that caused global warming

The biggest mass cataclysm of all time, called the end-Permian extinction, occurred 252 million years ago. Some 95% of species disappeared on land and at sea as a result of global warming

Another period of extreme volcanic activity 201 million years ago marked the end-Triassic mass extinction. It has been linked to the breakup of the Pangea supercontinent and the opening of the central Atlantic Ocean. 

Colder temperatures and a drastic drop in sea levels — perhaps as much as 10 degrees Celsius (18 F) cooler and 150 meters (492 feet) lower, respectively — played a major role in the earliest identified mass extinction event, the end-Ordovician, according to Benton. 

That shift, which took place about 444 million years ago, led to the disappearance of 80% of species at a time when life was mostly limited to the seas.

CNN 23 December 2023

https://edition.cnn.com/2023/12/23/world/mass-extinctions-explained-scn-climate/index.html

After a terrible year of climate news, here are 5 reasons to feel positive

A surge in renewable energy

A climate deal that targets fossil fuels

Plummeting deforestation in Brazil

The ozone layer is healing well

Electric vehicle sales surge

CNN 23 December 2023

https://edition.cnn.com/2023/12/23/climate/climate-five-reasons-positive-intl/index.html

There have been five mass extinction events in the history of the earth

https://englundmacro.blogspot.com/2023/08/there-have-been-five-mass-extinction.html