Global warming to cause widespread ocean deoxygenation by 2030's

According to a study by the US' National Center for Atmospheric Research (NCAR), there is an apparent reduction in the amount of oxygen dissolved in oceans due to climate change. The deprivation will be widely noticeable across large regions of the Earth's oceans between 2030 to 2040.

“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," NCAR scientist Matthew Long said in a statement.

Long is the lead author of the study, which was published in the journal Global Biogeochemical Cycles.

The study posits that the global warming could gradually deplete oxygen in ocean, leaving marine life, especially those in ocean depths, struggling to breathe.

"Loss of oxygen in the ocean is one of the serious side effects of a warming atmosphere, and a major threat to marine life," Long said.

The researchers discovered that deoxygenation caused by climate change could already be detected in the southern Indian Ocean and parts of the eastern tropical Pacific and Atlantic basins. However, the study shows that at least in some parts of the ocean—including areas off the east coasts of Africa, Australia, and Southeast Asia—deoxygenation from climate change may not be evident even by 2100.

Long’s team devised a map of the time frame in which climate change-induced ocean deoxygenation will become discernible.
 

^{Deoxgenation due to climate change is already detectable in some parts of the ocean. New research from NCAR finds that it will likely become widespread between 2030 and 2040. Other parts of the ocean, shown in gray, will not have detectable loss of oxygen due to climate change even by 2100. Image courtesy Matthew Long, NCAR}

The timeline is useful for deciding where to place instruments to monitor ocean oxygen levels in the future.

"We need comprehensive and sustained observations of what's going on in the ocean to compare with what we're learning from our models and to understand the full impact of a changing climate," Long said. — Kiersnerr Gerwin Tacadena/TJD, GMA News