Since the formation of the Earth, there have been 5 mass extinction events. The most recent was 66 million years ago during the Cretaceous period, leading to the extinction of the dinosaurs (Cosmos, 2019). However, in recent decades, more and more scientists have started to believe that we may be entering a 6th mass extinction, with many believing that it has already begun (Gingerich, 2020).

A ‘mass extinction’ or ‘extinction event’ can be defined as a rapid and widespread loss in biodiversity (Gingerich, 2020). With the IUCN predicting that 99.9% of critically endangered species and 67% of endangered species may be lost within the next 100 years (IUCN, 2019), there are strong indicators for the presence of a 6th mass extinction event. 

6th mass extinction

Cumulative vertebrate species recorded as extinct or extinct in the wild by the IUCN (2012). Dashed black line represents background rate. This is the ‘highly conservative estimate’. Source: Ceballos et al. (2015).

The human population is estimated to reach nearly 10 billion by 2050 (UN, 2019), so there will be even further increases in demand and consumption. This increasing population is threatening biodiversity in the following ways:

 

Why is biodiversity important?

importance of biodiversity ecosystems services

Source: de Knegt, Bart. (2019).

The Takeaway

The 2019 ISPBES Global Assessment Report on Biodiversity and Ecosystem Services suggests that human activity has directly resulted in 1 million plant and animal species facing extinction (ISPBES, 2019). 

“if all species currently designated as critically endangered, endangered, or vulnerable go extinct in the next century, and if that rate of extinction continues without slowing down, we could approach the level of a mass extinction in as soon as 240 to 540 years” (Greshko, 2019).

This article was written by Lizzie de Lusignan.

References
IUNC Report (2019) International Union for Conservation of Nature Marine life, fisheries increasingly threatened as the ocean loses oxygen. Retrieved 02 December 2019 from https://www.iucn.org/news/marine-and-polar/201912/marine-life-fisheries-increasinglythreatened-ocean-loses-oxygen-iucn-report.
(Aerts, Honnay & Van Nieuwenhuyse, 2018) – https://academic.oup.com/bmb/article/127/1/5/5051732
Isbell et al, 2011 – https://www.nature.com/articles/nature10282?page=7
United Nations, Department of Economic and Social Affairs, Population Division (2019). World Population Prospects 2019: Highlights (ST/ESA/SER.A/423). https://population.un.org/wpp/
Foley, J.A., DeFries, R., Asner, G.P., Barford, C., Bonan, G., Carpenter, S.R., Chapin, F.S., Coe, M.T., Daily, G.C., Gibbs, H.K. and Helkowski, J.H., 2005. Global consequences of land use. science309(5734), pp.570-574.
Perrings, C. and Halkos, G., 2015. Agriculture and the threat to biodiversity in sub-saharan Africa. Environmental Research Letters10(9), p.095015.
Poore, J. and Nemecek, T., 2018. Reducing food’s environmental impacts through producers and consumers. Science360(6392), pp.987-992.
de Knegt, Bart. “Indicators of Ecosystem Services for Policy Makers in the Netherlands.” Atlas of Ecosystem Services. Springer, Cham, 2019. 285-290.