The same human activity that is causing the world’s oceans to warm, rise, and acidify is also robbing those same oceans of oxygen. Furthermore, the impact of ocean suffocation on the planet is equally as alarming as the impact of climate change. Matthew Long, an oceanographer at the National Center for Atmospheric Research, states that climate change-driven oxygen loss in oceans is already easily detectable and that certain swaths of oxygen-deprived, or “suffocated,” oceans will likely be widespread in a mere 15 years.
Ocean deoxygenation is well established and refers to the loss of oxygen in bodies of water due to climate change, according to Ocean Scientists.
“Long-term ocean monitoring shows that oxygen concentrations in the ocean have declined during the 20th century, and the new IPCC 5th Assessment Report (AR5 WG1) predicts that they will decrease by 3-6% during the 21st century in response to surface warming. While 3-6% doesn’t seem like much, this decrease will be felt acutely in hypoxic and suboxic areas, where oxygen is already limiting. […] To put this in context, a highly optimistic emissions scenario of atmospheric CO2 levels of 550 ppm by 2100 would lead to a 1.2°C warming of the upper ocean. Therefore, these declines in oxygen are changes we should be prepared to see.”
In an interview with the Huffington Post, Long said that oxygen-deprived oceans may have “significant impacts on marine ecosystems.” An ocean that as been suffocated will be all but uninhabitable for certain species of marine life. Some sea life, such as dolphins and whales, receive their oxygen through surfacing and breathing air like we do. But most sea life rely on oxygen that has either entered the ocean from the atmosphere or has been released into the ocean waters by phytoplankton through the process of photosynthesis.
Simply put, studies already show that, as the ocean surface warms, it does not absorb as much oxygen. Furthering the problem is the fact that the oxygen found in warmer water is less dense, and doesn’t circulate into deeper waters as well as the oxygen found in cooler waters.
Long’s study of the suffocation of the oceans, which was published in Global Biogeochemical Cycles, used simulations in order to predict and calculate ocean deoxygenation through the year 2100.
Long explained the study in a statement.
“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 study’s findings were ominous.
In the near future, by the year 2030 or 2040, deoxygenation of the oceans caused by climate change will be “detectable in large swaths of the Pacific Ocean, including the areas surrounding Hawaii and off the West Coast of the U.S. mainland.”
Other areas, such as the seas near the eastern coasts of Africa, Australia, and Southeast Asia have more time, the study states — perhaps until 2100 before the deoxygenation caused by climate change is evident — but it will happen in those areas, as well.
A suffocated ocean may affect the ocean’s ability to sustain a healthy ecosystem. There is a deep concern within the scientific community, Long said, that “we’re conceivably pushing past tipping points” in being able to prevent the damage.
Climate scientist Michael Mann shared these concerns with Long in an interview with the Washington Post. He says that Long’s study is yet another addition to the “list of insults we are inflicting on the ocean through our continued burning of fossil fuels.”
Mann spoke urgently of the damage to the planet.
“Just a week after learning that 93 (percent) of the Great Barrier Reef has experienced bleaching in response to the unprecedented current warmth of the oceans, we have yet another reason to be gravely concerned about the health of our oceans, and yet another reason to prioritize the rapid decarbonization of our economy.”
And although the impact of the suffocation of the oceans due to climate change is variable throughout the world, the bottom line is that we don’t have long, the study warns.
[Image via Shutterstock]