Saturday, 8 November 2014

Anthropogenically Influenced Extinction

Calculating the effect that humans have on species extinction rates is an incredibly complicated and arduous process. The most common method is to attempt to calculate the rate at which species were becoming extinct before humans became a primary contributor to extinction. This is known as the 'background extinction rate'. Once a rough background extinction rate has been calculated, the current level of extinction rates are measured and then the two are compared. However, even this simple comparison poses many complications. One such complication is that from both past and present, it is not known how many species there are on earth. Therefore, it can be very complicated to ascertain an accurate calculation. It is also important to not only measure extinction rates, but to measure non-extinction rates; which as previously stated, can be complicated due to uncertain species numbers. However, with all efforts made to calculate and control the highlighted variables, how much of an impact are humans having on current species extinction? What is the modern day anthropogenically influenced extinction rate? 

The low estimated figure of species on earth is approximately 2 million. The maximum anticipated figure of species on earth is approximately 100 million. This leaves a huge gap for negotiation. To be more exact, it leaves the existence of a possible 98 million species to be negotiated. This however, is slightly beside the point. Regardless of the number of species alive on the planet today, it has been calculated that current day, human influenced species extinction rates, are between 1,000 and 10,000 times higher than the background extinction rate. The background extinction rate is anticipated to have been 0.1 extinction per million species per year. This means that if modern day extinction rates are calculated using the lower extinction estimate of 1,000 times more than the background extinction rate, then there are now 100 extinctions per million species per year. 

The statistics become incredibly daunting when the number of species per year going extinct are highlighted. For example, if the lower estimate of 2 million species on earth is accurate, then it is calculated that between 200 and 2,000 species extinctions occur each year. This means the earth looses roughly 2.7 species each day. Even more daunting is when the higher species estimate of 100 million is used in the equation. If there are 100 million species alive on earth then it is calculated that between 10,000 and 100,000 species extinctions occur each year. This means the earth looses between 1 and 11 species per hour, with the average being 1 species lost every 10 minutes. 

Daunting is not the word.

This massive human influenced extinction has been nick-named the 6th great extinction event of our planet; and it has been estimated that 99% of all extinctions that occur today, are somehow linked to human behaviour. Not all of the news is bad though. Due to advancements in technology and the wonderful and highly tenacious people that undertake conservation projects across the globe, some species are being saved and slowly revived. However, these efforts need to be maintained and improved if we are to be in with any chance of reducing this massive environmental crisis. 

A list of 100 animals you will never see, due to already being extinct. 

These 5 animals are currently endangered. If human behaviour remains constant your children may never seen these animals. 

A collage of currently endangered animals.

A daunting graph which shows the drastic increase in species extinction rates.

- Until the next Butterfly...