Researchers from the University of British Columbia have discovered that the Paris Agreement's global warming target of 1.5 degrees Celsius would be the answer to increasing potential fish catch by six million metric tons each year.

Published in the journal Science, the research revealed that the world's oceans are more sensitive to changes in temperature. "The benefits for vulnerable tropical areas is a strong reason why 1.5 C is an important target to meet," shared lead author William Cheung, director of science at the Nippon Foundation-Nereus Program and associate professor at UBC's Institute for the Oceans and Fisheries. "Countries in these sensitive regions are highly dependent on fisheries for food and livelihood, but all countries will be impacted as the seafood supply chain is now highly globalized. Everyone would benefit from meeting the Paris Agreement."

Utilizing computer models to simulate changes in global fisheries and analyze potential losses and gains, the researchers were able to compare the Paris Agreement 1.5 C warming scenario to the 3.5 C already pledged. For each degree of Celsius decrease, potential fish catches could increase by more than three metric million tons per year.

"Changes in ocean conditions that affect fish stocks, such as temperature and oxygen concentration, are strongly related to atmospheric warming and carbon emissions," shared Thomas Frölicher, another author of the research and principal investigator at the Nippon Foundation-Nereus Program as well as the senior scientist at ETH Zürich. "For every metric ton of carbon dioxide emitted into the atmosphere, the maximum catch potential decreases by a significant amount."

With climate change forcing fish to move to cooler waters, fishing management becomes more difficult since the number and species of fish caught around the world becomes more unreliable. In the Indo-Pacific area, there would be a potential 40 percent increase in fisheries catches at 1.5 C warming versus 3.5 C while the Arctic, despite losing sea ice, would see a greater number of fish under 3.5 C.

"If one of the largest carbon dioxide emitting countries gets out of the Paris Agreement, the efforts of the others will be clearly reduced," explained Gabriel Reygondeau from the Nippon Foundation-Nereus Program and another author of the research. "It's not a question of how much we can benefit from the Paris Agreement, but how much we don't want to lose."