Earth’s oceans may be sitting on a precipice of major extinction.
A new study has found that if humanity does not intervene and global warming continues unabated, life in Earth’s oceans could suffer mass extinction – a loss of biodiversity that could surpass the planet’s previous major extinctions.
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Risk of extinction for marine species
The study, published in the journal Sciencestates that the emission of huge volumes of human greenhouse gases into the atmosphere is fundamentally changing the Earth’s climate system.
These unprecedented changes are putting many species at risk of extinction. In order to unearth the stark reality of the situation, a team of researchers, Justin Penn and Curtis Deutsch, used extensive ecophysiological modeling that assessed the physiological limits of a species with respect to predicted sea temperature and oxygen conditions for assess the likelihood of extinction of marine species under conditions of various climate warming scenarios.
Penn and Curtis found that if global temperatures continue to rise at current rates, marine ecosystems around the world are likely to experience mass extinctions comparable to the size and severity of the extinction at the end of the Permian, the “Great Death” . This extinction occurred about 250 million years ago and wiped out 57% of biological families, 83% of genera, 81% of marine species and 70% of terrestrial vertebrate species. The scientific consensus is that the reasons for the late Permian extinction were high temperatures and widespread ocean anoxia and acidification caused by the massive volumes of carbon dioxide generated by the eruption of the Siberian traps.
An extinction event comparable to the “Great Dying”
The team also found patterns in future extinction risk: tropical oceans, for example, are predicted to lose most species to climate change, most likely to move to higher latitudes and more suitable conditions to survive. . On the other hand, polar species are likely to become extinct if their habitats completely vanish from the earth.
In addition to climate-related warming of the oceans and oxygen depletion, there are also direct human impacts such as habitat destruction, overfishing and coastal pollution that endanger marine species. And with the rate of catastrophic climate change, the future of ocean life as we know it remains unknown. However, there is hope, as the study also found that reducing or reversing greenhouse gas emissions could reduce extinction rates by up to 70%.
And according to an IPCC report released in April, the time is “now or never”. Global emissions must peak by 2025 to meet the Paris Agreement goal of limiting temperature rise to 1.5 degrees Celsius, so they must decrease 43% by 2030 from 2019 levels. Only then there can be hope.