Sunday 18 November 2018

The possible effects of an el-Nino


As El Niño sets in, will global biodiversity collapse in 2019?


17 November, 2018


[ Will global biodiversity collapse in 2019? ]

recent study created an original dataset of plant temperature tolerances with a median upper tolerance limit of 23.7°C.

This temperature is about 10°C higher than the temperature in the year 1750.
Only during times of mass extinctions were temperatures that high, such as during the 
PETM, 55.5 million years ago, and the Permian–Triassic extinction event, 252 million years ago, also know as the Great Dying when some 95% of species known from fossils went extinct.

[ image from: How much warmer is it now? ]
 
The study concludes that extinction will already occur far earlier than when upper tolerance levels are reached, as "loss of one species can make more species disappear (a process known as ‘co-extinction’), and possibly bring entire systems to an unexpected, sudden regime shift, or even total collapse."

There was a small group of species with large tolerance limits and remarkable resistance to environmental change, but even they could not survive co-extinctions. In fact, their extinction was abrupt and happened far from their tolerance limits and close to global diversity collapse at around 5 °C of heating.

In the top image on the right, monthly NASA Land+Ocean temperature data 2017-October 2018 are adjusted, and a polynomial trend is added, showing how a 5°C rise in temperature could occur very rapidly, i.e. by September 2019. 
[ El Niño sets in ]

The second image on the right is from an earlier post that contains more background on the adjustment of NASA data and the need for a polynomial trend.

A strong abrupt rise in temperature could be caused by an influx of warm salty water into the Arctic Ocean triggering large eruptions of methane from its seafloor, as discussed in earlier posts such as 
this one.

As El Niño sets in, the odds of a rapid global biodiversity collapse are rising.

Large methane releases from the seafloor of the Arctic Ocean could also be triggered by earthquakes. 


Above image shows a Magnitude 6.8 earthquake that occurred near Greenland on November 9, 2018, and subsequent nearby earthquakes measuring M5.2, M4.6 and M4.3 on the Richter scale. There is a danger of isostatic rebound triggering earthquakes in the Arctic Ocean that can in turn destabilize methane hydrates. This is discussed in more detail at 
this page.

Ominously, levels of methane as high as 2787 ppb were recorded on November 15, 2018. As the image below shows, very high methane levels were present over the Arctic Ocean (the magenta color indicating methane levels of 1950 ppb and higher).

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

Links

• Co-extinctions annihilate planetary life during extreme environmental change, by Giovanni Strona and Corey Bradshaw (2018)
https://www.nature.com/articles/s41598-018-35068-1

• Doomsday by 2021?
https://arctic-news.blogspot.com/2018/11/doomsday-by-2021.html

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

• Feedbacks
https://arctic-news.blogspot.com/p/feedbacks.html

• Extinction
https://arctic-news.blogspot.com/p/extinction.html

• Seismic Events
https://arctic-news.blogspot.com/p/seismic-events.html

• Can we weather the Danger Zone? 
https://arctic-news.blogspot.com/2018/07/can-we-weather-the-danger-zone.html

• How much warmer is it now? 
https://arctic-news.blogspot.com/2018/04/how-much-warmer-is-it-now.html

• What Does Runaway Warming Look Like?
https://arctic-news.blogspot.com/2018/10/what-does-runaway-warming-look-like.html

• Peaks Matter
https://arctic-news.blogspot.com/2018/08/peaks-matter.html

• Warning of mass extinction of species, including humans, within one decade
https://arctic-news.blogspot.com/2017/02/warning-of-mass-extinction-of-species-including-humans-within-one-decade.html


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