A debate going on in the scientific communities about the benefits of fertilizing the oceans with iron as a way to combat global warming. The theory behind iron fertilization is to remove CO2 gas from the environment by creating phytoplankton blooms. In large sections of the oceans, traces of iron are scant. Iron is one of the trace elements that brooms depend on to grow.
Marine plankton blooms are made up of both phytoplankton and zoo-plankton. Carbon is an important element, because it is the key element of life. CO2 is composed of two atoms oxygen bonded to one atom of carbon. A carbon sink is nothing more than a vast storage of carbon on the earth, and the oceans are the earth’s largest carbon sinks. The carbon cycle depends on the motions of air and water and on a number of physical, chemical and biological processes to transport it from one sink to the next. Carbon is very important to all life on earth in that it makes up 50% of the dry weight of living organisms.
Iron is one of the trace elements occurring neutrally in sea water that fertilizes phytoplankton blooms, but in certain oceans of the world, iron as a trace element is low, and as a result, the occurrence of plankton blooms are low. In the past, Researches have added low concentrations of iron to southern oceans and have created massive algae blooms. The reasoning behind these experiments is that phytoplankton uses CO2 to manufacture chlorophyll through photosynthesis. When the Phytoplankton dies, it settles to the bottom of the ocean. Any depth that dead phytoplankton sinks below the 100 ft to 200 ft level, removes CO2 from the environment for hundreds or even thousands of years.
World industries view iron fertilization as an cost effective way of cutting down on carbon emissions and there by combating global warming. In theory, industries would fund fertilization projects thought the purchase of carbon credits to offset CO2 emissions that they produce in manufacturing processes. There are many schemes to spread iron including from ocean freighters on their normal trade routes in areas of the deep ocean where iron levels are low.In any event,continuous fertilizing would be needed because iron settles out in sea water relatively fast.
A rough estimate suggests the worlds oceans contain 36,000 gigatonnes of carbon with in marine bio mass and also suspended in sea water as the bicarbonate ion. (A gigatonne being 1 trillion kilograms.) #World wide, phytoplankton plays a major roll in the uptake of CO2. According to satellite imagery, phytoplankton accounts for half of all the photosynthesis on earth and as a result absorbs roughly half of the CO2 produced by human activity ans through natural processes.
Those in favor of fertilization point out that according to satellite observations in the late 1990s, the worlds phytoplankton blooms have decreased since the early 1980s. It is theorized that this decrease is do to better world wide methods of soil conservation. (Less iron rich soil is being carried from the land to the oceans through wind erosion.) It is predicted that restoring plankton blooms to pre 1980 levels could reduce atmospheric CO2 levels by as much as 3-4 billion tons. This is half the amount of the man made global warming surplus. Proponents of iron fertilization say that they want to bring blooms back to these 1980 levels. Proponents of iron fertilization point out that a lot of CO2 is used up in calcification or the forming of shells by marine organisms and all of these tiny shells sink to the bottom. They say that Iron fertilization is absolutely vital to restoring the oceans health.
Skeptics say that not enough is known about the life cycling of plankton blooms. There is questions of how these blooms conserve gases in the upper layers of the oceans. Experiments are being conducted to track a plankton bloom over an 180 day span. Researches want to find out how much dead phytoplankton actually reaches the bottom of the ocean. Some research preformed at Stanford and Oregon State Universities suggests that ocean fertilization may not be efficient in reducing green house gases all together. Carbon levels were compared in the surface layers and the deep ocean. Less carbon was transferred to deep waters during the summer time blooms than during the rest of the year. By iron Fertilization an artificial summer bloom condition is created. Zoo-plankton grazes on Phytoplankton blooms and CO2 is given of by zoo-plankton in respiration. The CO2 given off by zoo-plankton remains in the upper layers of the ocean in its gaseous state.
Artificial fertilization introduces iron into the ocean environment far faster than ordinary occurs in natural carbon cycles. Iron fertilization may only delay the release of CO2 into the atmosphere. Some researches suggest that 95 percent of organic matter formed in the surface layers decompose there, while only 5% of dead phytoplankton sink into the deeper ocean. Some researches calculate that deep ocean carbon reservoirs are eventually exposed to the atmosphere through deep ocean up welling. The problem is that there is not enough verifiable knowledge about the oceans and the carbon cycles in sea water. We do not want to think of iron fertilization as a solution to global warming, when in fact a lot of financial resources are being wasted funding fertilization projects that either do nothing worse still could harm the marine environments. More research is needed.
