How is ETL measured and what is the current ETL for the human race?

Once established as a measure, every event and activity can be expressed in terms of its impact on the Extinction Threat Level, be that positive or negative. The impact and relationship between activities can be very complex and are open to debate. The accuracy of the reported ETL will vary, but over time should improve. In reality, the accuracy is less important than the debate prompted and also, one hopes, the common purpose recognised - to reduce the ETL for the human race.

Initially, the collective expertise used to set the Doomsday Clock would be a good starting point for calculating the current human ETL. The Doomsday Clock is set based on inputs from an esteemed board of sponsors, which includes the President of the Royal Society Lord Rees, the well-known scientist Dr Stephen Hawking and 18 Nobel Prize winners. In the future, an independent institute could be set up to calculate, report and improve the accuracy of the human species ETL.

There is a proposed scale for the ETL, which is detailed below:

Extinction Threat Level Scale (Bessant scale) - 5 zones with 401 minor units

Please do view or download the Extinction Threat Level scale pdf  for a fuller explanation of the scale, the different zones and the concept of the Extinction Horizon (EH).

The Universal Extinction Constant

Extinction Threat Level   (ETL)

ETL zone    =

ETL zone 0

ETL zone 1

ETL zone 2

ETL zone 3

ETL zone 4

ETL zone 5

ETL value    =


0.01 to 0.99

1 to 1.99

2 to 2.99

3 to 3.99


ETL colour  =            
(Please refer to the Extinction Threat Level scale pdf for full details).

Examples of the Zone defintions:-

ETL Zone 0 - This is unachievable, at least within the bounds of our known universe. It represents a total elimination of extinction risk. In other words, a level of knowledge and control that is beyond our comprehension. This represents as much a rebirth as the survival of a species.

ETL Zone 4 - A species in the upper part of this zone is already well on the path to extinction. The danger is greater for a dominant advanced sentient species, as there is unlikely to be any external intervention to help recover the situation.

ETL Zone 5 - This represents the total extinction of the species, the end. Currently, for human beings this may come much sooner than it needs to.

What is the Current Extinction Threat Level?
Based on this scale, the current human ETL is estimated to be approximately 3.67, so we are in the upper half of the final fourth (or red) zone. Worse still, we have driven other species to extinction, and continue to threaten the existence of many others, thus impacting the delicate balance of our eco-system and increasing our own ETL. It is also a huge concern that the most pressing threats are self-inflicted through our uncontrolled industrialisation and propensity for conflict. Time is not on our side and our current ETL rating reflects this. As an advanced sentient species, it is vital that we try to reduce our ETL.