The Fate of the Ocean
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Even as we spend millions looking to space for dangerous asteroids that might threaten all life on earth, we are the asteroid that has already landed. A modeling study from the National Center for Atmospheric Research in Colorado suggests that global warming, not an asteroid strike, triggered the earth’s most severe extinction event 251 million years ago during the Permian-Triassic era, long before the dinosaur die-off. Atmospheric CO2, fueled by massive earth-building volcanic eruptions in Siberia, warmed the ocean to depths of 10,000 feet, increasing salinity, shutting down the ocean conveyor belt, and trapping oxygen and nutrients so deep that most of the world ocean became a hypoxic dead zone. With hardly any sea life left to scrub the atmosphere of carbon dioxide, global warming accelerated. In the end, the Great Dying came close to destroying all life on earth, precipitating the demise of 95 percent of all marine species and 70 percent of all terrestrial vertebrates, leaving fungi to rule the world for many an eon.
AT NO TIME IN HUMAN HISTORY has so much scientific inquiry been focused so intensively in one direction: on the anthropogenic changes in our world. As a result, we are learning more, and more quickly than ever before, about how the life-support systems of earth work. Science now recognizes that the ocean is not just a pretty vista or a distant horizon but the vital circulatory, respiratory, and reproductive organs of our planet, and that these biological systems are suffering. Much effective treatment is suggested by computer-modeling studies, which the Bush administration, with its fear of science, negates—even though computer models are the same powerful tools that enable us to put men into space, to run wars, and to forecast financial trends.
Back aboard Oceanus in the stormy North Atlantic, we’ve reached the Gulf Stream at last, where the seas have stretched out with the increased depth, easing our ride a little. Surrounded on every horizon by menacing black skies, complete with downpours and bolts of lightning, we bask for an hour or two in a spotlight of sunshine that illuminates the endless cobalt of the deep, the platinum spray of the surface. Three of us—Ruth Curry, Guy Mathieu, and I—are out on deck tending the CTD, which has just returned from its four-hour journey to the bottom of the ocean. Mathieu, a retired scientist with the Lamont-Doherty Earth Observatory, is collecting samples from the Niskin bottles for analysis of their chlorofluorocarbons—those synthetic chemicals in refrigerants and aerosols so damaging to the Earth’s ozone layer, yet so useful as tracers for measuring the timescale of movements within the ocean conveyor belt.
Curry taps the bottles for oxygen analysis, and I follow up collecting salinity samples. Although conditions are wet, rough, and slippery, we smile, enjoying our time on deck. Five hundred miles from land, we are deep inside the embrace of the ocean, and as we work, we are touching water that an hour or two ago rode the Deep Western Boundary Current 17,000 feet deep, headed for Antarctica. The sea, always a place of awe, is made even more awe inspiring by the feel of its cold, buried tides.
In late 2005 a British oceanographic team, conducting research similar to Curry’s, announced findings that the Atlantic MOC—the critical factor keeping the North Atlantic warm—has slowed by 30 percent. Although the surface Gulf Stream apparently still flows as usual, the deeper waters are undergoing massive, silent changes, with virtually all of these shifts rapidly taking place since 1998.
But aboard Oceanus, this news is still six weeks in the future, and we are happy, at least in this moment, to be at sea in bad conditions collecting good data that may well lead to bad news. The tempest around us is beautiful yet seemingly manageable—that is, until the winds, whistling steadily at 40 knots, increase sharply, ripping off the whole surface of the sea, not just the tops of the swells. The whistling grows ominously louder and splits into harmonics of deeper- and higher-pitched voices. Literally over our heads, the low-pressure storm systems have merged, and within the hour we’re running south as fast as Oceanus will go.
No one who survives time at sea is ever less than humbled by its powers over life.
Julia Whitty is the author of the forthcoming book There Are Many Souls Embodied in Water: Tales From the Coral World. She has been making nature documentaries for the past 25 years, specializing in underwater films.
