New research from the U.S. National Center for Atmospheric Research indicates that climate change should drastically spread existing levels of oxygen loss in the oceans from 2030-2040.
Oxygen reductions are already identifiable in the southern Indian Ocean and segments of the eastern tropical Pacific and Atlantic basins, according to the findings. Supercomputer-enabled modeling indicated that the level of detectable climate-change oxygen loss would be “evident across large regions of the oceans” in roughly two decades, a press release from the University Corporation for Atmospheric Research says. However, such oxygen loss was not projected as far out as 2100 in east coastal zones of Africa, Australia, and Southeast Asia, among other regions, the researchers found.
Warmer surface waters soak up less oxygen from the atmosphere or via photosynthesis, and what oxygen does enter would be more likely to stay near the surface in the heated, lighter water. Lower oxygen levels would threaten a broad swath of sea life.
“Loss of oxygen in the ocean is one of the serious side effects of a warming atmosphere, and a major threat to marine life,” NCAR scientist and study lead author Matthew Long said in the release. “Since oxygen concentrations in the ocean naturally vary depending on variations in winds and temperatures at the surface, it’s been challenging to attribute any deoxygenation to climate change. This new study tells us when we can expect the impact from climate change to overwhelm the natural variability.”
The study, funded by the National Science Foundation, was published in the journal Global Biogiochemical Cycles.