The "Deadly Trio" of Carbon Dioxide Threatens the World's Oceans

Earth’s oceans are currently more acidic than they have been in at least 300 million years, according to a report released today by the International Program on the State of the Ocean (IPSO). If that's the case, it's a condition that may have shoved us mostly unawares into the next great extinction event.

The IPSO researchers explain that acidification is one of three primary symptoms currently threatening our planet’s waters. The other two members of what they coined the “deadly trio” are ocean warming and deoxygenation. While all three have their own unique and detrimental effects on the ocean, they are all connected by a single source of causation: carbon dioxide.

Beyond their common carbon history, this triad is otherwise significant because “most, if not all, of the Earth’s five past mass extinction events have involved at least one of these three symptoms of global carbon perturbations," reads the report. But how did it get this way?

While we’ve been scurrying to better understand climate change on land, the vast “buffer” that is the world’s oceans has been absorbing excess carbon dioxide. In a sense, the organization writes, “it has been shielding us from the worst effects of accelerating climate change.” This might seem good for us land-dwellers in the short-term, but in the long term, as carbon dioxide accumulates in the Earth’s waters, acidity increases, everything gets warmer, and oxygenation drops.

Higher acidity eats away at coral, which is in itself an ecosystem for other marine animals. Problems with coral mean problems for a whole collection of other marine organisms. “At carbon dioxide concentrations of 450-500 ppm (projected in 2030-2050) erosion will exceed calcification in the coral reef building process, resulting in the extinction of some species and the decline of biodiversity as well,” IPSO notes.

Over the last century, the ocean has warmed 0.6 degrees Celsius. While it might not sound like a lot, it is already causing species to scatter and biodiversity to drop. Coral is also affected by warming as well. Between that and acidification, IPSO predicts that coral reefs will be a thing of the past by 2050.

And lastly, deoxygenation leaves us with dead zones, which have been doubling in number every decade since the 1960s. As the ocean’s oxygen levels decrease over the next forty years by anywhere from one to seven percent, we can only expect these trends to continue.

The “deadly trio” isn’t the only grim matter about which IPSO seeks to warn us. In a series of five articles published in the Marine Pollution Bulletin, IPSO researchers discuss a spectrum of anthropogenic repercussions of our current relationship with the ocean. In one paper, the organization focuses on our misunderstanding and misuse of the high seas, a “frontier” region with resources that are being exploited by the United States. In another, IPSO insists that we stop preemptively congratulating ourselves for making curtailing overfishing, because we still are faced with frightening depletions of biodiversity.

It’s a lot to process. While we already knew some elements of this report—that oceans are acidic, that temperatures are rising, that dead zones are becoming more common—the power of IPSO's research is that it shows to what degree acidity, warming, and deoxygenation are effecting the ocean. Its bleak conclusions mirror those from the IPCC report of last week. If this indeed represents the current condition of our oceans, then we need to recalibrate our perspectives and realize that “the future of humanity and the future of the ocean are intertwined.”

@heyiamlex