Citat:
Det är ett alarm av många, många.Det här påminner också om "Den stora döden" som inträffade för många miljoner sedan och som forskare nu har studerat. Jorden blev ca 10 C varmare under några hundra år. Syret i haven minskade väldigt kraftigt och det tros ha orsakat att merparten av växter och djur blev utrotade.
The 'great dying': rapid warming caused largest extinction event ever, report says
Rapid global warming caused the largest extinction event in the Earth’s history, which wiped out the vast majority of marine and terrestrial animals on the planet, scientists have found.
The mass extinction, known as the “great dying”, occurred around 252m years ago and marked the end of the Permian geologic period.
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Up to 96% of all marine species perished while more than two-thirds of terrestrial species disappeared. The cataclysm was so severe it wiped out most of the planet’s trees, insects, plants, lizards and even microbes.
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The great dying event, which occurred over an uncertain timeframe of possibly hundreds of years, saw Earth’s temperatures increase by around 10C (18F). Oceans lost around 80% of their oxygen, with parts of the seafloor becoming completely oxygen-free. Scientists believe this warming was caused by a huge spike in greenhouse gas emissions, potentially caused by volcanic activity.
The new research, published in Science, found that the drop in oxygen levels was particularly deadly for marine animals living closer to the poles. Experiments that varied oxygen and temperature levels for modern marine species, including shellfish, corals and sharks, helped “bridge the gap” to what the model found, Payne said.
“This really would be a terrible, terrible time to be around on the planet,” he added. “It shows us that when the climate and ocean chemistry changes quickly, you can reach a point where species don’t survive. It took millions of years to recover from the Permian event, which is essentially permanent from the perspective of human timescales.”
https://www.theguardian.com/environment/2018/dec/06/global-warming-extinction-report-the-great-dying
Men visst är det en tröst att vi kan välja vad vi vill tro på. Än så länge.