If what happened 252 million years ago is anything to go by, then we can expect a mass extinction very soon.
Scientists in Australia and New Zealand discovered a current trend of tropical fish and marine life fleeing their home in the equator to relocate to cooler waters. These tropical waters have become too hot for some species to survive, caused largely by global warming, forcing them to move further afield.
The implications of such a change on marine ecosystems, and human livelihoods are monumental, explain the scientists in their study, and could trigger a mass extinction — something that happened at the end of the Permian Period, 252 million years ago, when, as a 2020 study discovered, around 90 percent of all marine species died.
The scientists published their study in the journal PNAS.
History repeating itself
The difference between what happened millions of years ago and now is that the past's mass extinction took place after volcanic eruptions released huge amounts of CO2 into the atmosphere and water, heating the global temperatures by 50 degrees Fahrenheit (10 degrees Celcius) over tens of thousands of years, which lead to a mass extinction.
Nowadays, however, the change has been brought on due to human-driven climate change, and only took hundreds of years to get to such a critical stage. Even though the change in global temperatures isn't as high as 252 million years ago, it's still enough to shift species out of their habitats.
In their latest study, the scientists observed distribution levels of some 50,000 marine species collected since 1955, and the increasing dip proves that tropical marine species have been moving towards the poles due to warming equatorial waters.
What does this mean?
Ecosystems could end up suffering as species moving away from their tropical ecosystem reduces the ecological resilience to environmental changes.
Subtropical ecosystems see more species joining their sights, which will bring in species invaders, and new competitiveness between species, which could lead to an ecosystem collapse, as species go extinct.
On top of all of that, human livelihoods that depend on fishing tropical species will face significant challenges, too. Fishers will have to move further afield if they want to meet their fishing quotas, sometimes endangering themselves in the process.
A mass extinction can be prevented, advise the scientists, if we take action now.
One major method would be to reduce our carbon emissions, and to protect our oceans and their biodiversity. Well-known natural history broadcaster Sir David Attenborough pointed out five actions humans can fully embrace right now to minimize the disastrous effects our planet, and our oceans, will face in the future, including mass extinction of marine life.