A new study by the National Center for Atmospheric Research (NCAR) claims that the reduction in oxygen dissolved in the oceans due to climate change will be apparent across large portions of the world's oceans between the years 2030 and 2040. Although scientists know that global warming will likely suck the oxygen out of the oceans over time, studies examining its impact have been hazy regarding its current impact until now.
"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, an NCAR scientist and lead author of the study. "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."
The team used simulations to examine dissolved oxygen and determine how much variability in its concentrations took place in the past. Using this data, they determined when the deoxygenation of ocean oxygen due to climate change will trump any point modeled throughout history.
The results revealed that deoxygenation stemming from climate change might already be significant enough to be detected in the southern Indian Ocean and parts of the eastern tropical Pacific and Atlatnic basins. In addition, they determined that more widespread detection is likely between 2030 and 2040, although some regions of ocean, such as the east coasts of Africa and Australia, will not show evidence of deoxygenation caused by climate change until 2100.
Using the same data, the team was also able to create maps of oxygen levels in the oceans and determine which patterns stemmed from natural weather phenomena and those that were caused by climate change and global warming.
"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.
The findings were published in the Feb. 29 issue of the journal Global Biogeochemical Cycles.
