It seems that every week, a new study comes out showing just how much damage we’re doing to our planet. This last one’s a doozy, though: according to Matthew Long, an oceanographer at the National Center for Atmospheric Research, if we continue along the road we’re on, the ocean could begin to suffocate in about 15 years. Actually.
The study was published a few days ago in Global Biogeochemical Cycles, which is not The National Enquirer and is a publication entirely based on science. Long’s not some quack, either. He’s a dyed-in-the-wool scientist with a Ph.D. in Oceanography from Stanford University, an M.S. in Environmental Engineering (Hydrology) from Tufts University, and a B.S in Environmental Engineering. That is a man who likes facts.
According to Ocean Scientists for Informed Policy, “ocean deoxygenation refers to the loss of oxygen from the oceans due to climate change.” It’s not up for debate, either: it is a cold and hard fact that both climate change and ocean deoxygenation are happening, and no amount of climate change deniers stamping their feet will change it.
“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,” the website explains. “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.”
While it seems obvious that an ocean deprived of oxygen is a bad thing, let’s break it down real quick: Almost everything in the ocean depends on the oxygen in the water to survive. Of course, there are a few things that don’t–whales, dolphins, turtles, and other creatures that surface to breathe–but for the most part, everything takes oxygen from the water. If those things die, that’s a pretty massive big ball rolling towards everything else being dead.
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.)
So how does climate change affect the ocean? Well, the ocean is warming up, and a warm ocean doesn’t take in as much oxygen from the atmosphere, for starters. There’s the whole sea level rising issue, which is just way too big to go into here. But possibly the most concerning part of the whole thing has to do with phytoplankton, which are one of the smallest, most prolific, and really fucking important creatures on earth. If you believe National Geographic, “fish, whales, dolphins, crabs, seabirds, and just about everything else that makes a living in or off of the oceans owe their existence to phytoplankton, one-celled plants that live at the ocean surface. Phytoplankton are at the base of what scientists refer to as oceanic biological productivity, the ability of a water body to support life such as plants, fish, and wildlife.”
Warmer water doesn’t mix well with colder water. As the surface warms, the phytoplankton that float around up there most of the time don’t get down deep as often, and those little guys are responsible for about half of the oxygen in the ocean.
Until the recent study, blaming climate change on the dropping levels of oxygen in the ocean was a tough sell, even to those who aren’t turning a blind eye to one of the hugest problems humans have ever faced. It was a tough sell because it was almost impossible to prove in nature. When it’s windy, for example, it churns everything up, making it nearly impossible to get an accurate measurement over a long period time. Long’s study cut out the variables of Mother Nature and all her vagaries. “This new study tells us when we can expect the impact from climate change to overwhelm the natural variability,” he said.
Using simulations, he predicted and calculated ocean deoxygenation until the next century. And holy Christ, was it ever bad news. According to the predictive study, vast portions of the Pacific–Hawaii and the western edge of the Americas included–will be seriously deprived of oxygen somewhere between 2030 and 2040, which would most likely mean massive die-offs of very important creatures.
Although Long’s study is far more telling than any other before it, it’s not really anything all that new. Back in 2010, Scripps Institution of Oceanography warned about the dangers of something called “oxygen minimum zones”, which are exactly what they sound like: large portions of the ocean, usually very deep, that don’t have enough oxygen to really sustain much life. “A major concern is that these so-called oxygen minimum zones (OMZs) will expand in the future as the upper ocean warms and becomes more stratified,” wrote Scripps scientist Ralph Keeling.
What does it all come down to? Well, more and more, it seems we’re already too far gone. Every day, we’re passing tipping points. Long, who seems a little frustrated that no one in charge is listening to him or anyone else that has been screaming about a host of environmental issues, made his point very clear. “This inexorable force of human-induced warming will clearly result in widespread ocean deoxygenation in the future,” he said.
And like it or not, our lust for carbon is causing it. “This latest study adds one more item to the list of insults we are inflicting on the oceans through our continued burning of fossil fuels,” said Michael Mann, a climate scientist at Penn State University. “Ocean life and marine ecosystems must now simultaneously contend with the triple threat of warming waters, increased acidity, and now, we’re learning, lower oxygen levels. Any one of these challenges alone would be daunting. “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.”
