The fast depleting levels of oxygen in the oceans will choke the marine life without oxygen by 2040s, said a study based on a simulation in super-computer.
Without oygen, known as ocean deoxygenation, the marine life including fish, crabs, squid, sea stars, sharks, and other marine life cannot breathe and eventually become extinct.
“Loss of oxygen in the ocean is one of the serious side effects of a warming atmosphere, and a major threat to marine life,” said Matthew Long from US National Centre for Atmospheric Research (NCAR).
“Since oxygen concentrations in the ocean naturally vary depending on variations in winds and temperature 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,” Long said, in the study that was published in the journal Global Biogeochemical Cycles.
The oceans absorb oxygen from surface atmosphere from from phytoplankton, which releases oxygen into the water through photosynthesis. But warm surface makes it difficult for oxygen to sink deeper into the ocean due to heated upper surface water does not filter oxygen to lower levels.
The impact of climate change on deoxygenation, simulated on the Yellowstone supercomputer, which is operated by NCAR’s Community Earth System Model, ran more than two dozen models between 1920 to 2100 to study the emerging phenomenon.
The research team found that deoxygenation in the southern Indian Ocean and parts of the eastern tropical Pacific and Atlantic basins is widespread and by 2030 and 2040, the region would go without oygen in the ocean.
While it took millions of years for Earth to become mildly oxygenated, from being originally anoxic, the climate change impact may reverse the atmosphere and the marine life in oceans to pre-atmospheric oxygen-less stage.