The news from the Deepwater Horizon catastrophe keeps on worsening. First, we heard about a piddling 1,000 barrels per day. That number was from the Coast Guard. Then, there was a quick rise upward to 5,000 barrels daily. Then, rumors suggested about 12,000 to 19,000 barrels per day was more likely. BP and Obama administration spokespersons alike hushed us: Fifteen-thousand barrels a day, folks. This is no Exxon Valdez. Don’t worry a bit! Of course not, why would we? Now, the government and BP are admitting to the “range” of 35,000 to 60,000 barrels a day, and, to quiet surging rage, have acquiesced to a 20 billion dollar escrow fund. Perhaps, in several weeks, the escrow fund will be doubled and BP’s spokesperson will start mumbling about the possibility that their own higher-end estimates of 100,000 barrels per day are accurate, while BP engineers plunk increasingly complex Rube Goldberg devices down onto the streaming wound.
But imagine that none of it had happened at all. Imagine running the last 70 days backward. Marsh grasses dying from oil loaded with chemical dispersants poisoning their roots coming back to life; seabirds turning from tar black to white; corpses of dolphins and whales floating backwards out to sea from the estuaries and wetlands in which they’d washed up, then, the rims of their blowholes clearing from the asphyxiating oil; crabs suddenly coming back to life and scuttling around; ships speeding in reverse to their normal stations, the rubber containment booms going back into the ships’ holds and the floors of the rubber rafts; the metal platform rising sturdily from the sea; the firefighting ships’ water hoses absorb rather than spray water. Then, the flames, instead of leaping out from the exploding rig, leap back into it and disappear; the oil, blowing out in brown-black clouds deep underwater, slowly getting sucked into the pipe and, then, the pipe seals shut and the machinery of deep-sea oil production proceeds apace.
And, then, the Gulf of Mexico disappears from the news, too. Maritime pollution is not the subject of near-daily editorials in the major newspapers. The health of the seas is suddenly out of vogue. Meanwhile, all of the petroleum that’s lurking in emulsified columns beneath the surface of the Gulf instead is incinerated, transformed into CO2 (carbon dioxide). But at least the Gulf of Mexico is spared ecocidal levels of contaminants right?
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Not right. Not even close.
First, the marine ecosystems of the Gulf have been literally dying for decades. Most summers, an immense zone of oxygen-depleted seawater runs from the Louisiana continental shelf to the Texas coast, what aquatic ecologist Nancy Rabelais characterizes as the “largest such zone in coastal waters of the Western hemisphere.” Severe oxygen depletion has two levels: hypoxia, less than 2 mg of oxygen per liter – or 3 mg in some systems – and anoxia, 0 mg of oxygen per liter. Oxygen depletion in the Gulf comes from the confluence of several biological and physical processes. First, nutrients which arrive on the waters of the Mississippi and flow out into its delta and beyond, into the Gulf, cause intense biological activity, which leads to oxygen depletion. The Mississippi’s waters are unusually loaded with nutrients, mainly nitrogen, but also phosphorus, because they are dumped onto farmland in the form of fertilizer further upstream and inevitably percolate into the water table and the tributaries that converge into the Mississippi. As Scott Doney of the Woods Hole Oceanographic Institute adds, “About half the global riverine nitrogen input (50 to 80 Tg of [nitrogen per] year) is anthropogenic in origin … and anthropogenic nitrogen deposition is concentrated in coastal waters downwind of industrial and intensive agricultural regions.”
Then the detritus remaining from the algal blooms that are fed by nutrient oversupply and the fecal pellets produced by zooplankton decompose. The decomposition process uses oxygen and that rate of oxygen use exceeds the rate of oxygen resupply. This process is exacerbated by the way freshwater flows in from the Mississippi, leading to marine water stratification – separation of the water into different strata, or levels. This occurs year round due to differences in the salinity level of freshwater and seawater, but is worsened in the summer due to warming of the surface waters and calming winds, which prevent intense mixing of the waters – at least until hurricane season begins. When fish or other sea life enter these hypoxic or anoxic zones, they literally suffocate due to inadequate oxygen supplies. These zones expand every year. Globally, there are more than 400 such coastal hypoxic systems. The area they cover is more than 245,000 square kilometers and as Doney adds, “Population growth and further coastal urbanization will only exacerbate coastal hypoxia without careful land and ocean management.”
More broadly, it is not just the Gulf of Mexico that is experiencing changes in its chemical composition. The ocean itself is chemically transforming due to the rise of atmospheric CO2 levels, which have risen from 280 parts per million (ppm) before the Industrial Revolution to about 390 ppm today. Rising CO2 in the atmosphere leads to some of that excess CO2 dissolving in surface seawater, through what Doney characterizes as “well-known physical-chemical reactions.” He adds, that the “global uptake rate is governed primarily by atmospheric CO2 concentrations and the rate of ocean circulation that exchanges surface waters equilibrated with elevated CO2 levels with subsurface waters.” Scientists estimate that the total ocean intake of carbon since the start of the industrial age amounts to about 25 to 30 percent of total human CO2 emissions. The ocean has been a major sink for human-produced CO2, but maybe not for long, and not without tremendous ecological cost.
When oceans absorb anthropogenic CO2, their chemistry changes. They become more acidic (lower pH levels) and have “lower chemical saturation states” for calcium carbonate (CaCO3) minerals. Sea-based organisms use those minerals to make their shells and skeletons. The two forms which are most frequently used by those organisms are aragonite, used by most mollusks and coral generally, and calcite, used by coccolithophores – single-celled algae, protists and phytoplankton – foraminifera and other mollusks. Surface seawater is currently supersaturated with those forms of calcium carbonate, while its quantity decreases with depth. When water is undersaturated, shells and skeletons can start to dissolve.
Scientists believe that an increase in ocean acidification, an inevitable consequence of increasing atmospheric CO2, will probably reduce the growth of shells and skeletons for such species as corals and mollusks. At 550 ppm of atmospheric CO2 – a level we will hit if we continue on the trajectory plotted by every planet-killing compact the world has considered in recent years at its soirées in Copenhagen and Bonn – coral reefs begin to erode, instead of grow, because of oceanic acidification and the warming of surface waters. Right now, at this very moment, “ocean pH is lower than it’s been for 20 million years and it’s going to get lower. [The] acidification resulting from the current carbon dioxide emissions is massive and rapid,” comments science writer Richard Kerr. It would be a world without coral, because we insist on bumbling around in SUVs and having 11 carrier-strike groups trawling the world’s oceans, securing the supply lines for a substance that is destroying life within the realm they motor above.
The fantasy of a pre-Deepwater Horizons’ blow-out world ends up looking pretty bleak. Ecocide still takes place – it’s just that there aren’t 300-foot high flame jets blowing out of ruptured oil rigs to alert us to its presence. It’s quiet death: slow acidification of the oceans, to the point that oysters and other organisms have trouble forming their shells, coral can’t accrete and metastasizing hypoxic zones, in which small immobile organisms asphyxiate when they enter and fish either circumnavigate or enter and die. And there are no “top-kill” or “relief well” techno-fixes to resurrect the ocean when we’ve killed it, a pleasant way to punctuate the arrival of the Anthropocene era, as a group of scientists dubbed the current geological era.
So, in a morbid way, we can be thankful for one thing: At least powerful people are looking at the Gulf of Mexico and the ongoing horror there. The question is how to make them see all of the problems and their interlinks and fix all of them and not bluster and blather about climate change bills that won’t change anything, and techno-fixes that are hyper-elaborate, Promethean devices that attempt to treat the symptoms when the problem isn’t safely extracting oil. It’s that oil extraction isn’t safe because oil isn’t safe.
The people in the global South have it right: There’s already too much CO2 in the atmosphere. The question is how to bring the increases to a screeching halt, now. Will Obama take that up at the Cancun summit in late fall? I doubt it. I doubt it unless we make him.