Ever wondered what happens to all the carbon generated into the atmosphere? Well, there are natural means and mechanisms set in place for the removal and storage of the carbon, or specifically speaking, the carbon dioxide and this process is known as carbon sequestration. When done artificially, the carbon sequestration process can be used to store or remove carbon dioxide for longer-term and thus it can help in slowing down the process of global warming and mitigating climate change implications. Natural carbon sinks suck up the carbon dioxide gas present in the atmosphere and store them within themselves. With the Kyoto protocol, the awareness of these carbon sinks has grown among the public over the years as they can be used to offset carbon emissions by anthropogenic activities. Soil, plants and oceans are natural reservoirs or sinks which store carbon and its compounds and help limit the heat-trapping carbon dioxide in the atmosphere.
When carbon dioxide is removed from the atmosphere and stored in the soil carbon pool, it is known as soil carbon sequestration. Soil can hold more carbon than the combined holding capacity of plants and atmosphere. The ability of soil to sequester carbon depends on the amount of organic matter it has. Soil rich in decomposed plant and other organic matter can hold more carbon. However, with increasing deforestation and land degradation, much of the soil, all across the globe, has eroded significantly leading to a massive release of carbon back into the atmosphere. Like soil, plants and trees too can capture carbon dioxide for the process of photosynthesis and thus can store a considerable amount of carbon from the atmosphere.
The largest sinking capacity comes from our oceans including marine soil and vegetation. CO2 is easily dissolved in water and it is estimated that oceans can capture up to one-fourth of the total carbon emission produced due to human activities. However, with the growing concentration of CO2 in the atmosphere, there has been a rise in temperature leading to global warming. The warmer ocean water find it difficult to hold carbon dioxide and hence the harmony of this carbon sink too has been disturbed by human activities!
In recent years, scientists, taking a cue from natural processes of carbon sequestration, have been working on sequestering the carbon from the atmosphere by the artificial mechanism. The carbon is captured at the source of the emission and it is then sunk or buried. In Artificial ocean sequestration, the captured carbon dioxide is injected deep in the ocean under high pressure, where it is expected to dissolve in water over time. In geological sequestration, it is buried deep into geologic formations such as aquifers or old oil reservoirs. Another sequestration method is mineral sequestration where captured carbon is buried in areas rich in minerals like Magnesium or Calcium, where carbon dioxide reacts with these minerals to form respective carbonates! Artificial carbon sequestration processes can help in our fight against climate change but only to an extent. Moreover, there needs further research in deploying artificial carbon sequestration technology as we still do not know what negative impacts or dangers it can pose us to.