Extinction of Species

That some species go extinct is in fact quite natural and has been happening in natura for as long as it could have.

The rate at which species go extinct in this way is called the background extinction rate¹. Estimating this rate is very hard and estimated rates thus differ greatly.

It is however agreed upon that the current actual rate of extinction far superseeds that of the background extinction, being 100 or possibly thousands times larger. ²

Mass extinctions

1. 66 million years ago - End of Cretaceous
2. 199 million years ago - Late Triassic
3. 252 million years ago - End of Permian: largest event
4. 378 million years ago - Late Devonian
5. 447 million years ago - Late Ordovician: due to cooling climate

Accelerating rates of extinction

After the great industrialisation and the massive growth of human population seen since the 1800s the rate of extinction has increased and keeps doing so ^{2 3}.

Current number of species threatened by extinction

Depending on what constitutes a species threatened by extinction and who you ask you’ll get different current estimates.

• 1 million - the 2016 IPBES Global Assessment ³
• >15 thousand - Smithsonian ²
• 35 765 - on the 2020-3 IUCN Red List (VU, EN or CR) ⁴

IUCN Red List

The IUCN categories that are included on the Red List are:

• VU - Vulnerable
• EN - Endangered
• CR - Critically Endangered

Norwegian red list by Artsdatabanken

In my province in Norway there are 448 species on the current Norwegian red list from 2015. ⁵

Some of these are

English	Norwegian	Latin	Status
Mountain fox	polarrev	Vulpes lagopus	CR
Common skate	storskate	Dipturus batis	CR
Mountain fox	polarrev	Vulpes lagopus	CR
Common murre	lomvi	Uria aalge	CR (LC globally)
Wolverine	jerv	Gulo gulo	EN (LC globally)
Black-legget kittiwake	krykkje	Rissa tridactyla	EN (VU globally)
Lynx	gaupe	Lynx lynx	EN (LC globally)
Rose fish	vanlig uer	Sebastes norvegicus	EN
Snow owl	snøugle	Bubo scandiacus	En (VU globally)
Razonbill	alke	Alca torda	EN (NT globally)

These lists are made by Artsdatabanken in accordance with the guidelines set by the international organisation IUCN.

A new and updated version is in the works for 2021!