The devastating effects of climate change are all too visible on land in the form of extreme weather events, but it’s changing conditions underwater too.
Most ocean environments will change due to climate change and it could have huge knock-on effects both on sea life and on communities which depend on it.
The researchers found that 60% to 87% of the ocean is expected to experience multiple biological and chemical changes, such as increases in water temperature, higher levels of acidity and changes in oxygen levels, by the year 2060.
The rate of change is expected to be even higher, 76% to 97%, in very large marine protected areas such as Australia's Great Barrier Reef Marine Park and the Galapagos Marine Reserve in Ecuador.
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"What we're looking at here is the potential extinction of a whole environment," said Watson, who specialises in marine social-ecological systems and understanding complex adaptive systems.
"In some places, the environments we have today are not going to exist in the future. We won't be able to go visit them or experience them. It is an environmental, cultural and economic loss we can't replace."
Increases in pH, which measures ocean acidity, are expected as soon as 2030.
Ocean acidification reduces the amount of carbonate in seawater, which is necessary for marine organisms, such as corals and molluscs like oysters, to develop their shells and skeletons.
The findings were published this week in the journal One Earth.
Using the last 50 years of ocean conditions as a measure of stability, the researchers used several climate models to see how six variables affecting ocean conditions might change as the planet warms.
They used three warming scenarios with increasing degrees of severity.
Steven Mana'oakamai Johnson, a postdoctoral researcher at Arizona State University said,"Our scenarios included likely, unlikely and highly unlikely degrees of warming, all of which are warmer today than they were 20 years ago.
“In all three scenarios, conditions in more than half of the ocean are going to be novel, meaning new and significantly different, than they have been in the last 50 years."
Much of the change occurs in the ocean's two extremes: the tropics and the Arctic. The warmest places are seeing warming conditions never seen before, and the coldest places, like the Arctic, are no longer as cold as they once were.
The researchers also found that most of those changes will occur by 2060, though most of the change in pH, or acidity, levels is expected much sooner, by the end of the decade.
The change is more pronounced for the very large marine protected areas that are designed to preserve threatened species and rare habitats such as coral reefs around the world. As ocean conditions change, animals in those protected areas are likely to seek other locations that are more favorable for their survival.
"These marine protected areas are an important tool for achieving conservation goals and can take a lot of political and social will to establish and work as intended," Johnson said.
"In our analysis, 28 out of 29 of these areas will experience changes in conditions that could undermine conservation goals."
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