Carbon Sequestration

Climate Change
April 15, 2010

Swept Under the Rug

Many factors may contribute to global warming. Burning of precious fossil fuels, substandard emission techniques, and an ever growing population all play an intricate role of raising Earth’s overall temperature. Each can be linked through one key adversary, carbon dioxide. Rising CO2 levels are almost the sole reason temperatures are rising at such an alarming rate. Aside from water vapor, carbon dioxide is a chief ingredient in our Greenhouse Effect stew. It’s everywhere. It emits from our cars, it flies from our smokestacks, and it empties from our lungs. All of Earth is in consensus that CO2 levels must be lowered or even maintained at their present levels. Even with nearly seven billion people on Earth, only three tangible tactics have been made to combat carbon dioxide. The most obvious approach is to lower the amount of energy used. This can be done by the world either using less energy through conservational behaviors or to acquire more efficient technology to reduce consumption. The second and less popular method is to adopt energy uses that release no carbon dioxide. Finally, and as unpopular as the kid-who-picks-his-nose, the process of capturing carbon dioxide from the fossil fuels that are burned and storing it deep into the Earth’s crust. All of these methods have the good intention of lowering CO2 but each have chink in their crystal armor. Generally humans are lazy, and do not look past their nose let alone into the future. Those in developed countries are too comfortable in their ways to change, so energy conservation is out. Underdeveloped countries are too concerned with aggrandizing their current situation and do not care for expensive alternative energy, so zero emission energy is done. The only realistic attempt of lowering carbon dioxide levels is to accept our flaws as humans and take responsibility for our evil ways. CO2 must be taken from our smokestacks and mufflers, and then swept under the rug.
Carbon sequestration is the practice of varying processes to store carbon dioxide for a long period of time. This concept is developed and practiced for the sole reason of mitigating global warming. Carbon sequestration comes in many forms that benefit differing assemblages. The techniques range from biological, chemical and physical.
The biological side of carbon sequestration consists of encouraging photosynthesis to lower atmospheric CO2. This can be done in numerous ways. Planting grass between crop growing seasons or simple reforestation are small scale examples of biological carbon sequestration. It does come in larger sizes though. Phytoplankton within the euphotic zone of large bodies of water account for over half of the photosynthetic activity on Earth. In attempt to boost the growth of the Earth’s phytoplankton, certain fertilizers could be added to our oceans and lakes. This process is known as ocean nourishment. In 2007, an Australian company called Ocean Nourishment Company conducted an experiment by sinking one ton of urea off the coast of the Philippines. Urea is nitrogen rich fertilizer that stimulates phytoplankton growth. Its results are still being processed.
The chemical processes of carbon sequestration are less tangible to the human hand. CO2 can be stored within the earth’s crust by naturally occurring chemical reactions. When CO2 reacts with a metal oxide, a carbonate is produced, thus eliminating a molecule from the atmosphere. The reaction is exothermic and favors lower temperatures.
CaO + CO2 → CaCO3 This reaction generally takes place as weathering upon rock containing CaO or MgO transpires over a long period of time. Humans aim to accelerate the entire process by stacking the deck. It has been proposed to pump gigatons of CO2 into the ocean. This allows the CO2 to dissolve into the seawater and react with the oceanic rocks called basalt. This reaction releases calcium and magnesium ions, both easily converted into the carbon storing components. Physical efforts to lower CO2 levels involve large amounts of burial. This includes concealing both biomass and compressed CO2. Burying of biomass, such as crop waste or dead plants, traps the CO2 of the decomposing material in the ground and imitates the natural sequence of the formation of fossil fuels. This is different from landfills as it only allows organic materials to be buried. This technique may also be practiced in the ocean. Barges of plant matter are sunk into the ocean at an attempt of carbon sequestration. CO2 can also be taken from the air itself. This can be done at one of the sites of the main causes of elevated Carbon dioxide levels. A popular location for carbon capture is at power plants that utilize fossil fuels. CO2 can be taken both before and after the combustion of the fuel. Prior to combustion, the fossil fuel is reduced to a gas containing carbon monoxide, methane and hydrogen. When this mixture is heated (but not combusted), carbon dioxide is released. It is then scrubbed from the gas using absorption through ammonia particles. Post combustion, carbon is actually removed from the emitted pollutants. Often in the cooling towers, amine groups such as monoethanolamine bind with carbon dioxide and is extracted from the air. After either pre or post combustion carbon capture, the retrieved CO2 is cooled and compressed. The compressed CO2 is then either transported or stored. Options for storing are controversial. It can be pumped into the ocean as mentioned earlier or it can be siphoned into depleted fossil fuel reservoirs. In some instances with oil, the CO2 can actually be pumped into the oil reservoir to create pressure to retrieve the oil. Almost half (47%) of the emissions that are produced are able to be treated for carbon sequestration. This means that three million metric tons of CO2 can be obtained through carbon capturing methods and can be prevented from further contributing to greenhouse effect. As populations see how essential carbon capture is to reducing global CO2 levels, more money may be granted to finding new ways to capture carbon from our emissions (scrubbers attached to mufflers, in-home sequestration methods, etc.). Ample depleted reservoirs are scattered not only across the United States, but also the world. The empty reservoirs contain enough volume to store annual carbon dioxide emissions multiple times over.
Country/region
Coal
Petroleum
Natural gas

Reserves
Production
Reserves
Production
Reserves
Production

United States
184.0
0.64
3.6
0.30
3.0
0.29
Russia
117.1
0.15
9.0
0.42
26.2
0.33
China
85.4
1.24
1.9
0.16
1.3
0.03
India
69.0
0.22
0.7
0.03
0.6
0.02
Australia
58.6
0.23
0.5
0.02
1.4
0.02
Middle East
0.3
0.00
90.2
1.11
39.4
0.16
Total world
678.2
3.23
145.8
3.59
98.4
1.51 *in gigatons

Carbon sequestration can be a double-edged sword. Many experts have their doubts about the man-made methods that could fail or even further harm the planet. They view the panacea as a mere placebo. One of the largest skepticisms about pumping large amounts of C02 into the ocean could irrevocably change its pH. As carbon dioxide is dissolved into water, its pH becomes slightly acidic. Many of the ocean’s flora and fauna are fragile in habitat conditions and these environments would succumb to drastic changes as pH is modified. Earth could lose numerous species in a short period of time. Tinkering with the ocean’s balance may also be negative effected by another carbon sequestration application. The addition of fertilizers into the ocean may increase phytoplankton activity, but other flora may benefit from the nutrients. Different forms of algae may intake copious quantities of the fertilizers and an algae bloom may occur. Red tides are known for the mass killing of wildlife within its destructive force, and if fertilizers are added into the equation, the magnitude would grow exponentially. Burying of biomass may also disrupt delicate cycles. Plant cycles rely on the certain amounts of carbon returning to the soil and the burying of biomass out of a plant’s reach will inevitably contradict the overall goal of carbon sequestration, removing CO2 from the atmosphere in mitigation of global warming. Soils would become depleted of the nutrients that are essential to a plant’s growth, thereby reducing the active photosynthesis community. Fears of leakage of condensed CO2 into water tables under the Earth’s crust have come into sight. Although power companies claim stable reservoirs possession, the Earth’s lithosphere is constantly under pressure and is continually changing, leaving opportunity for CO2 seeping out. As a final skeptic aspect, one is faced with another contradiction as carbon capture and storage is scrutinized. The process of compiling and compressing the retrieved carbon dioxide from the emissions uses vast amounts of energy. Yes, it is convenient that the location of the carbon capture is at a power plant and the company may cut itself a deal, but fossil fuels will still be consumed to create the power that reduces the carbon dioxide it emits. This continuous loop is both costly to maintain and to the planet. The Earth has its own natural ways regulating its temperature by sequestering amounts of CO2, but it is the anthropogenic effect that has disrupted the balance. Humans have made a problem; they’ve identified it, and have ways to right their wrongs. Human practices of carbon sequestration show a much needed step in the right direction. Not only do these processes lower atmospheric carbon dioxide, it proves to the skeptics that humans are capable or taking initiative in combating human error. Carbon capture and storage instills a confidence in the belief that humans are not the cause of their own apocalypse. In an ideal world, carbon sequestration wouldn’t be needed nor would global warming be an anthropogenic liability, but this is not the case. Righting the wrongs is series of trial and error. Many of the carbon sequestration methods may not work, and may even worsen the current conditions but when one process is found that is fool-proof; humans may not need to feel as guilty as they let out a carbon dioxide rich sigh of relief. Many experts view carbon sequestration as merely sweeping of our dirt under the rug, yet man is solely responsible for the mess and is the only means of its refurbishing. No one else is looking; continue to sweep dirt under the rug. Charles Darwin gave humans the egocentric mindset of “Survival of the fittest,” and when backed into a self dug hole man must bury carbon before he buries himself.