Monday, May 24, 2010

Disaster in Slow Motion

Jim Reynolds

When I hear the term “worst-case scenario”, I usually dismiss it, thinking, “It will never get that bad.” My rationale in making this judgment is that things will change over time. Even so, the term has great value because if we are aware of how bad it might get, with enough lead time, we can prepare mitigation strategies so that “it will never get that bad.” The massive seafloor gusher in the Gulf of Mexico requires that kind of thinking and that kind of mitigation effort.

At first, the media harped that this disaster might rival the Exxon Valdez disaster in Alaska. That was a soft-sell; there was no need for the subjunctive tense. Within a matter of days, the Deepwater Horizon blowout will eclipse the Exxon Valdez and it may pass Chernobyl as the worst manmade environmental disaster on record. Given that the best-case predictions of capping the flow are still weeks, if not months, away, it is probably a good idea to roll out the worst-case scenarios and start strategizing about fighting it long-term as the contamination spreads.

Most media coverage about the Gulf catastrophe gives the impression that this is a local event and that the Gulf shoreline of Texas, Louisiana, Mississippi, Alabama, and western Florida, are destined for disaster. This is undoubtedly true for vast stretches of the coast. They will see the worst shoreline effects but this is not a local event; this disaster will affect a much larger area.

We could well be witnessing the first stages of a global environmental Armageddon as it unfolds before our eyes in slow motion. The petroleum slick will is now in the Loop Current which will accelerate dispersal of the Gulf slick and begin to convert it into the North Atlantic Ocean slick. Once the hydrocarbon raft starts moving with the current, it will spread throughout the Gulf of Mexico. A portion of it will escape the Gulf through the Florida Straits between the Dry Tortugas and Cuba, fouling the shorelines on both sides. Most of that water will continue up the Florida Straits, between Florida’s east coast and the Bahamas, while the rest spreads through the passages between the various islands of the Bahamas and the Turks and Caicos Islands. The ooze will continue to flow up the east coast of North America powered by the Gulf Stream. It would be wise for all East Coast states and Maritime provinces to prepare mitigation efforts similar to the valiant stand currently being made by citizens of the Gulf states.

Not all of that floating petroleum will be absorbed by North American beaches, estuaries, and wetlands. The Gulf Stream will carry part of it past Greenland and Iceland toward Europe where the Gulf Stream splits to form the North Atlantic Current, which flows northward into the Arctic Ocean, and the Canary Current, which flows southward along the west coasts of Europe and North Africa.

A small portion of the Canary Current branches off and flows into the Mediterranean. Petroleum that gets into the Mediterranean will stay there because there is no surface outflow. The rest of it begins to flow westward a few degrees north of the equator as the North Equatorial Current, eventually entering the Caribbean and returning to the Gulf of Mexico where the current flow cycle starts over again. Fortunately, there is very little surface water that crosses the equator, so it is likely that the slick can be contained in the North Atlantic and Arctic Oceans.

The North Atlantic (and Arctic) slick won’t be the chocolate brown goo that is being monitored in the Gulf at present. It is more likely to be a thin film, a fraction of a millimeter thick, with a colorful iridescent sheen similar to those often seen on puddles in parking lots.

The consequences of a thin petroleum film floating on the surface of the North Atlantic and Arctic Oceans need to be addressed. The film constitutes a barrier for oxygen exchange between the ocean and the atmosphere. Most near-surface life is comprised of zooplankton (animals) and phytoplankton (plants). Without oxygen this bountiful community of unicellular life will perish: the base of the food chain will disappear. Like falling dominos, the North Atlantic extinction will travel up the food chain. Fisheries will become a memory. Cultures that rely on seafood for sustenance, primarily in Africa, northern South America, Central America, and Caribbean island nations will need to adapt to a change of diet or face a similar fate.

The petroleum film will also impede water evaporation. If the solar energy that evaporates water is blocked, the only alternative is for the surface water temperature to rise. Warmer water will accelerate Arctic Ocean melting during the long summer daylight hours and impede refreezing during the long, cold, winter darkness. Arctic Ocean mammals such as polar bears, walruses, and other pinnipeds will probably not survive.

Fortunately, nature has its way of curing what ails it. Over a period of years to decades to centuries, or millennia, depending on how long it takes to plug the leak, the petroleum will decompose and life will slowly return to the poisoned oceans but it will be a different world. An ice-free Arctic Ocean will trigger dramatic climate changes. Increased summer evaporation will dump vast amounts of moisture on northern Eurasia and North America. In the winter months, it will fall as snow—lots of snow. Incoming spring sunlight will reflect back into space, cooling the planet. Melt water will enter the Arctic Ocean and float on top because it is less dense than seawater. Unlike today, surface water will flow out of the Arctic Ocean and override the warm but salty North Atlantic Current, sinking the heat supply that makes Northern Europe habitable. This could foment a return to Ice Age conditions while shortening growing seasons and sparking population migrations.

I provide these predictions as a worst-case scenario in the hope that there is enough lead time to rally mitigation efforts. Earth is an incredibly intricate and complicated system. The petroleum mega-leak disrupts important components and causes systemic ripple effects. If we don’t attack the problem with inspired mitigation, we could face a bleak future on both sides of the North Atlantic.

The media overuse the term “tipping point” to describe a rapid and dramatic climate change. We may be watching that tipping point gurgling out into the Gulf of Mexico on the evening news. This severe environmental catastrophe may turn into humanity’s greatest challenge. I hope not; I would love to be wrong but you should know about it.

Is there a solution? The best chance at mitigation is in the Straits of Florida between the Dry Tortugas and west of Havana, the narrowest passage the petroleum will have to flow through. If a floating weir were established, it could funnel the floating muck to a central collection point downstream, to the east. Any petroleum headed for the Atlantic must pass through this channel. This will take unprecedented cooperation between the U.S. and Cuba but too much is at stake to allow our differences to hinder the mitigation effort.

Reynolds is an Associate Professor of Geology at Brevard College, Brevard, NC.

An earlier version of this editorial appeared in the Transylvania Times, Brevard, NC.

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