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UBC researchers find potential fish catches would be six million metric tons a year higher if the global temperature goes up by just 1.5 degrees Celsius, compared with a jump of 3.5 CPASCAL ROSSIGNOL/Reuters

Sticking to international targets for global temperature increases could have a major benefits for fisheries around the world, researchers in British Columbia say.

A new study from the University of British Columbia finds potential fish catches would be six million metric tons a year higher if the global temperature goes up by just 1.5 degrees Celsius, compared with a jump of 3.5 C.

The Paris agreement – the latest international deal on mitigating the effects of climate change – aims to limit the average global temperature increase by a maximum of 2 C by 2050.

Experts have predicted if the status quo remains, the Earth's temperature would rise by at least three degrees.

There's a "strong relationship" between climbing temperatures and dropping fish stocks because as waters warm, fish either migrate to find cooler environments or die off, said William Cheung, the study's lead author and an associate professor at the university's Institute for the Oceans and Fisheries.

Fish stocks are already declining around the world and the numbers will drop even more substantially if global temperatures warm by more than 1.5 C, Prof. Cheung said, noting tropical waters around countries such as Thailand, Indonesia and the Philippines are especially sensitive.

"It means instead of a slowly decreasing catch as we get warmer and warmer in the tropical area, once we move past 1.5 to two degrees Celsius, the impacts will accelerate really rapidly," he said. "It is a good idea to achieve the Paris agreement to avoid the rapid impacts beyond that."

The study, published Thursday in the journal Science, estimates there would be 40 per cent more fisheries catches in the Indo-Pacific region at a 1.5 C increase compared with the 3.5 C bump. The Indo-Pacific is made up of the Indian Ocean and the western Pacific Ocean.

A higher jump in temperature could see more fish in the Arctic region, Prof. Cheung said, but the change would also see melted sea ice and increased pressures on the area's current fisheries operations, including indigenous fishermen.

Declining fish stocks could have negative impacts on the health of people in less-developed countries and disrupt the global supply chain in more developed countries, Prof. Cheung explained.

"Fish are important," he said. "There are people in the world who rely on fish and seafood for essential nutrients."

Having even one country opt out of the Paris agreement would have a devastating impact on fisheries, Prof. Cheung said.

U.S. president-elect Donald Trump has called climate change a "hoax" and pledged during his campaign to "cancel" the Paris agreement.

If the United States keeps its carbon emissions at "status quo" or expands the carbon sector, fish stocks around the world will decline, Prof. Cheung said.

"Everyone needs to commit more in order to achieve the Paris agreement target," he said.