Large swaths of the Earth’s oceans are being hammered by multiple climate impacts at once, scientists say — a trend that could spell long-term trouble for marine ecosystems and fisheries.
The impacts include changes in ocean temperature, salinity and dissolved oxygen. A study published last week in the scientific journal Nature Climate Change finds that 25 to 40 percent of the global ocean is experiencing at least two of these impacts at the same time. And an estimated 15 to 25 percent of the global ocean is experiencing all three at once.
Meanwhile, nearly 100 percent of the planet’s ocean cover is seeing an increase in its pH levels, a process known as acidification, driven by rising concentrations of carbon dioxide in the Earth’s atmosphere. That’s yet another climate consequence to add to the mix.
The impacts themselves aren’t new. Scientists have known for decades that many of Earth’s marine ecosystems are heating up, losing oxygen and becoming more or less salty, depending on the region. And studies have shown that human emissions of greenhouse gases are spurring these changes.
