Saturday, February 5, 2022

When will humans go extinct?

In a recent paper, Guy McPherson, Beril Sirmacek and Ricardo Vinuesa discuss Environmental thresholds for mass-extinction events. Authors point at an image by Song et al. (2021) that shows how major mass extinctions over the past 541 million years (the Phanerozoic) are linked to temperature rises higher than 5.2°C and rates of change higher than 10°C/Myr.

Earlier, a 2018 study by Strona & Bradshaw found that at 5°C rise, most life on Earth will be extinct (see box below on the right, from an earlier post).
In the video below, authors Guy McPherson, Beril Sirmacek and Ricardo Vinuesa discuss their analysis 'Environmental thresholds for mass extinction events'.

Authors point out that, next to temperature rise and rates of change, there are further variables such as rates of deforestation, ocean acidification and spreading of toxic substances that can additionally contribute to cause species to disappear.

Accordingly,  many species are likely to go extinct at rises much lower than 5°C. 

Humans - who depend on many species - could go extinct with a 3°C rise, as the above-mentioned earlier post concluded.

This makes it even more critical to assess how much the temperature has already risen from pre-industrial. As illustrated by the image below, we may already be more than 2°C above pre-industrial and face a potentially huge temperature rise over the next few years.

Below, the video associated with the analysis Environmental thresholds for mass-extinction events.

The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


• Environmental thresholds for mass-extinction events - by Guy McPherson, Beril Sirmacek and Ricardo Vinuesa (2022)

• Thresholds of temperature change for mass extinctions - by Haijun Song et al. (2021)

• Co-extinctions annihilate planetary life during extreme environmental change - by Giovanni Strona and Corey Bradshaw (2018)

• When Will We Die?

• Pre-industrial

• Climate Plan