A new study published on Tuesday by the National Academies of Science found that all the marine life in the ocean will decline by one-sixth by the year 2100 under the high emissions global warming scenario but on by 5% if we can stay within the low emissions scenario — with an average 5% decline for every 1 °C of warming. These losses are driven by temperature increases rather than fishing and were more significant in the tropics.
Why This Matters: These are some of the most renowned scientists when it comes to ocean productivity and their research provides an important contrast between best and worst case scenarios, which should motivate us to act to reduce global greenhouse gas emissions. As was made clear by the U.N. Extinction Report, we humans rely on the natural world for our existence. “Healthy oceans are required for planetary stability,” University of Georgia marine biologist Samantha Joye told the Associated Press (AP). The bad news is that if we don’t get greenhouse gas emissions under control, we will lose billions of fish that we need to feed the planet. But the good news is that if we can reduce our emissions and keep temperature increases lower, we can stave off a global food security disaster.
What Is New In This Study? Scientists already knew that climate change and ocean warming would reduce the amount of marine life (or biomass), but past computer simulations looked at only part of the picture or used only one model, whereas this study uses six different state-of-the-art computer models that give the best big-picture look yet, according to William Cheung, a marine ecologist at the University of British Columbia said.
The Biggest Losers: The AP reported that the largest animals in the oceans are going to be hit hardest according to study co-author Derek Tittensor, a marine ecologist at the United Nations World Conservation Monitoring Center in England. But there’s more — tropical areas, already warm, will also see the biggest losses, according to Cheung.
One Bright Spot: Study co-author Boris Worm, a marine biologist at Dalhousie University in Canada, told the AP the “good news” is the decline will be less heavy in smaller organisms that are “the main building blocks of marine life,” such as plankton and bacteria.