WASHINGTON – If global warming is a self-correcting phenomenon – that is, if planet Earth can be counted on to take care of itself at any cost in human disruption – then coral reefs begin to make sense as an early warning. They are constructed of millions upon millions of organisms; all growing toward surface light in oxygen-saturated clear water. They are useful, rare, varied, beautiful, all-consuming and quite possibly doomed, according to scientists and researchers cited in recent in-depth Guardian Weekly and New York Times analyses.
Twenty-five percent of the coral in the world has disappeared in the past 25 years, David Vaughan, director of the Center for Coral Reef Research at Mote Marine Laboratory in Florida, said in a Times interview. Another 25 percent of corals will disappear in the next 25 years, he added.
Global warming is a large part of their problem. The seas, their natural environment, are subject to a host of activities that threaten them. Until now they’ve survived well enough. But a consensus of opinion, strong and growing, argues that global warming is caused by the release of so-called greenhouse gases into the atmosphere, where they absorb heat from the sun and radiate it back to Earth. Foremost among the greenhouse gases is carbon dioxide, or CO2; as the seas absorb more of it from the atmosphere, their acidity rises. The heightened acidity kills off algae the corals absorb as energy. Without sufficient algae of the right kind, corals are at risk.
One of the early warnings corals offer the human species is that marine carbon sequestration faces some of the same ”ripple effect” problems associated with terrestrial and geologic carbon sequestration.
Carbon sequestration refers to the long-term purposeful isolation of carbon dioxide from the atmosphere. Stored for long periods in natural elements, CO2 can’t contribute to global warming.
Aside from its being a centerpiece of the campaign against global warming, carbon sequestration matters to Indian country because tribes that take advantage of forthcoming regulations governing the Indian title of the Energy Policy Act of 2005 are apt to encounter carbon sequestration as they enter the energy industry. Internationally, carbon sequestration programs have become a key component of carbon offset credit schemes.
But in all of its forms, carbon sequestration comes with a caution against ill-considered action. Terrestrial carbon sequestration emphasizes growing new trees to harbor CO2 through photosynthesis. But turning up soil to plant the trees, breaking them down to biomass or harvesting them for commercial use, involves a competing release of carbon dioxide that may nullify the gains of sequestration.
Geologic carbon sequestration, more accurately known as geologic carbon capture and sequestration, amounts to the capture of carbons released in manufacturing processes, followed by their injection into seams and pockets beneath the Earth’s crust. But social concern arose about the wisdom of impregnating the Earth’s crust for the long haul with carbon dioxide. The research and monitoring does not yet exist to put a firm foundation under comprehensive geologic carbon capture and sequestration.
Corals signal similar concerns about marine carbon sequestration, now in its infancy. Iron nourishes plankton, which absorbs carbon dioxide more or less as trees do. Commercial scientists and researchers hope vast fields of plankton will bloom in remote tracts of the oceans once the waters are fertilized with iron.
Terrestrial carbon sequestration has found favor with environmentalists for obvious reasons, and geologic carbon capture and sequestration has its leading advocates in the energy sector because it can prolong the productive life of oil fields while reducing carbon emissions.
Marine carbon sequestration gets its early backing from technological entrepreneurs, hoping to capitalize on the so-called carbon offset credits that are a common provision of international and European trade treaties – companies purchase a credit, at so much a ton of sequestered carbon emissions, that counts toward meeting a CO2 emission reduction standard established by regulation.
But it’s unclear how effective plankton can be at containing CO2. That it absorbs carbon dioxide from the atmosphere is certain. But the consensus seems to be that when it is devoured or decomposed, plankton releases captured carbon back into the atmosphere, just as trees do when felled or split, and fields when plowed.
Commercial efficiency relies on vast fields of plankton sinking to the sea bottom with a full complement of carbon still within them.
But will they carry enough carbon with them to make a difference? And at that point will they also release other elements, such as methane and nitrous oxide, which contribute to greenhouse gases? They will certainly increase oceanic acidity in their immediate environment, but will the faraway corals feel it?
In the rush to commercialize marine carbon sequestration through plankton blooms, no one so far knows the answers.
