While humans face the consequences of intense heatwaves, incessant rains, floods due to climate change, and unchecked emissions, they are not alone in suffering. The marine biodiversity is on track to face mass extinction if emissions remain unchecked by the end of this century. As global oceans warm and the melting of ice continues, biologists have revealed that marine biodiversity could be on track to plummet within the next few centuries to levels not seen since the extinction of the dinosaurs. Species losses from warming and oxygen depletion alone could push the marine world to the brink by the year 2100. The study published in the journal Science states that drastically reducing global emissions, however, offers substantial protection, which emphasizes a need for rapid action to prevent possibly catastrophic marine extinctions. The paper stated that global warming threatens marine biota with losses of unknown severity.
Polar species are at highest risk of extinction, but local biological richness declines more in the tropics. “Aggressive and rapid reductions in greenhouse gas emissions are critical for avoiding a major mass extinction of ocean species,” Curtis Deutsch, a professor of geosciences at Princeton, co-author of the study said in a statement. Deutsch along with Justin Penn, a postdoctoral research associate in geosciences, initiated the study when they were at the University of Washington by combining physiological data on marine species with models of climate change to predict how changes in habitat conditions will affect the survival of sea animals around the globe. They studied their survival in the coming centuries. “The extinction magnitude that we found depends strongly on how much carbon dioxide [C02] we emit moving forward. There’s still enough time to change the trajectory of CO2 emissions and prevent the magnitude of warming that would cause this mass extinction,” Penn said.
The researchers solidified their findings by comparing their model to past mass extinctions found in fossil records linked to the geographic pattern of Earth’s deadliest extinction event. The event, 250 million years ago, was driven by climate change and Oxygen depletion. They found that their model projecting future marine biodiversity follows a similar pattern as ocean temperature increases and oxygen availability drops, marine life abundance plummets. Water temperature and oxygen availability are two key factors that will change as the climate warms due to human activity. Warm water holds less oxygen than cooler water, which leads to more sluggish ocean circulation that reduces the oxygen supply at depth. “Marine animals have physiological mechanisms that allow them to cope with environmental changes, but only up to a point, researchers said in a statement, adding that they found that polar species are more likely to go extinct globally if climate warming occurs. The big concern is that climate change will make large swaths of the ocean similarly uninhabitable, Penn said adding, “extreme warming would lead to climate-driven extinctions that, near the end of the century, will rival all current human stressors combined.”
