As Planet Warms, Oceans Face Threatening Changes Unseen in 3 Million Years

New study predicts major disruptions to entire world ecology under both moderate and severe warming levels

by     Lauren McCauley, staff writer

Continued warming of the world's oceans may trigger disruptions to marine life not seen in 3 million years, according to a new study published Monday in the journal Nature Climate Change.

The study, put forth by scientists from the University of Science and Technology in Lille, France, and other institutions, aims to put the anticipated ecological crisis in historic perspective.

Among the foreseen changes are extinction of some of the ocean's keystone species as well as the widespread influx of invasive plants and animals particularly in "temperate and polar biomes."

"Climate change may rapidly reorganize marine diversity over large oceanic regions,” states the report. "The intensity of this reorganization will depend, unsurprisingly, on the magnitude of warming."

According to the report, a "moderate warming" scenario, with projected global warming ranging from 0.9 to 2.6º C, "will increase by threefold the changes already observed over the past 50 years."

However, of most concern is that severe warming, with a projected increase of 0.8 to 4.8°C, "will affect marine biodiversity to a greater extent than temperature changes that took place between either the Last Glacial Maximum or the mid-Pliocene and today," impacting as much as 70 percent of the world's oceans. 

The effects of both the moderate and severe scenarios will ultimately impact humans, saidco-author Richard Kirby, with Britain's University of Plymouth, as the global ecosystem will inevitably be altered.

"When the temperature of the environment changes, animals and plants change in abundance locally or may move to new locations if the habitat is suitable," Kirby said. "These movements ultimately affect the food web and ecology, and if they are rapid, the food web may become uncoupled."

The study, Kirby continued, highlights "the changes in the Earth’s biology that may lie ahead if we do not address global warming."

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