Rising levels of CO2 are making it hard for fish to breathe in addition to exacerbating global warming and ocean acidification
ClimateWire, May 2, 2016
Curtis Deutsch, associate professor at the University of Washington’s School of Oceanography, studies how increasing global temperatures are altering the levels of dissolved oxygen in the world’s oceans.
Scientists have been warning that decreasing amounts of available oxygen will increase stress on a range of species, even as they also face the effects of rising temperatures and ocean acidification.
Deutsch’s latest research is untangling how much oxygen loss is linked to climate change and how much is due to normal variation in oxygen levels.
“As the climate goes up, the amount of oxygen will go down, but it’s really hard to look in the ocean to see that change,” he said.
Using an earth system modeling approach, Deutsch and scientists at the National Center for Atmospheric Research and the Georgia Institute of Technology mapped out changing oxygen levels across the world’s oceans through the end of the 21st century.
They found that it was possible to distinguish the impact of global warming from other sources of oxygen loss. As soon as 2030 to 2040, climate-driven declines in oxygen levels will be detectable in oceans all over the globe. In some places, like the southern Indian Ocean and parts of the eastern tropical Pacific and Atlantic basins, evidence of climate-linked deoxygenation is already apparent, while other regions won’t see changes by 2100.
The researchers recently published their results in Global Biogeochemical Cycles.