Carbon capture and sequestration (CCS) is the method of capturing and storing carbon dioxide emissions from the atmosphere.
This new technology could play a big role in climate change on how we can reduce our carbon emissions in the world on natural and technological levels. This method has become very important based on how carbon dioxide is the leading greenhouse gas being released. The Global CCS Institute states that “The International Energy Agency (IEA) has estimated that to halve global emissions by 2050 (widely believed to be required to limit the temperature rise to 2ºC), CCS will need to contribute one fifth of the required emissions reductions, both in the power sector as well as the industrial sector” (Global CCS Institute 2018).
Knowing this information, it shows we need to change reduce our emissions and these new technologies of carbon sequestration could help save our planet on the rising temperature crisis of our planet.
Carbon can be captured and sequestered in natural ways in our ecosystems.
In forests it is found that carbon is sequestered through tree biomass. Carbon is stored in the cell walls of the plants and they have cells all over since the cells help keep the structure of the plant up. Plants go through photosynthesis to receive glucose and they need carbon dioxide from the atmosphere to go through this process. As the plant continues to go through photosynthesis they will increase in size, so in forests when trees grow, they increase in biomass adding to the forests overall biomass and can sequesters more carbon from the atmosphere. When there is deforestation in forests and trees start to decompose carbon is released back into the atmosphere. Depending on what the tree is used for if it’s being harvested for is how long or fast the carbon will take to release it. Trees cut down to make products like paper will release carbon very quickly but cutting down trees to make furniture will sequester for a longer period of time. Another way to sequester carbon is microphotosynthesis.
This process is explained “Within the soil, photosynthetic bacteria up to 200 mm can sequester CO2 from the atmosphere due to the fact that ultraviolet and infrared light rays are able to reach these bacteria and power the photosynthesis process” (Annual Reviews of Resource Economics 2012). Microphotosynthesis just goes through the soil and can stay underground for a long period of time. It works by carbon coming in contact with humus and it is decomposed for energy (Annual Reviews of Resource Economics 2012). Humus is the decomposition of plants by microorganisms in the soil. On top of sequestration in forests we can also look at in agriculture. Using carbon sequestration in the agricultural field can be beneficial as well. There are many strategies to go by in doing this, but the main idea is to take the carbon out of the atmosphere and hold it in the soil. The different strategies depend primarily on climate of the area, soil types, and geography of the agricultural field.
The main thing you want to do is to primarily use the soil as a sink. Soils have been losing carbon, while oceans and the atmosphere have been gaining it. It is problematic with soil losing carbon due to the need for it to grow crops. Another issue is conversions of grasslands and forests to croplands, this results in loss of organic matter in the soil. Soil carbon is made from plants, these plants go through life cycles of living and dying and when they die, they leave organic matter in the soil. Under certain conditions the plants are able to secrete the carbon dioxide to the atmosphere or save it back in the soil. Based on all of this it shows carbon can change forms and can be shown in different soil pools. Soils pools are nutrient reservoirs in the soil and can be classified as the fast/labile, slow, or stable pool. The fast pool turns over carbon within a few days to a few years, Labil pools are made of microbes and can sequester the most carbon, slow pool is made up of plant residues and takes about year to decades, and a stable pool ranges from centuries to millennials based upon the soil carbon compounds being resistant to disturbances slowing down the change (NSAC, 2015).
If the soil is managed in all these different types of pools, they have the ability to increase the soil carbon and cause atmospheric carbon to be drawn into it. The soil “can strongly influence this dynamic in four ways: 1.) Decreasing the level of soil disturbance (i.e. tillage) to enhance the physical protection of soil carbon in aggregates. 2.) Increasing the mass and quality of plant and animal inputs to soils. 3.) Improving soil microbial diversity and abundance. 4.) Maintaining continuous living plant cover on soils year-round” (NSAC 2015). To improve soil sequestration one important part agriculturally is to have aggregates in the soil. Particles of carbon are found in the center of the aggregates, this gives a physical protection in the soil. Microbes cannot penetrate aggregates, so the particles can protect the carbon inside.
When using tillage in farming practices that destroys aggregates leaving the carbon vulnerable to the microbes in the soil and are able to be broken apart. Some studies have shown using no tillage has greatly increased the aggregates forming more carbon in the soil (NCAS, 2015). In order to continue to have a lot of carbon in the soil though there has to be no tillage at all. Using any kind of tillage immediately reverses the processes removing all the carbon and aggregates in the soil. There’s another option of conservation tillage which allows fewer tillage per year and is less intense than normal. The majority of conservation tillage methods uses genetically modified seeds and chemical herbicides. This method still increases carbon, but sequestration works better with no tillage at all. They both increase soil carbon at the surface, but it is unsure of what happens in lower depths of soil where more aggressive tillage systems work. Tests were done on these two methods at lower depths to see how each would perform and no tillage was shown to be the better method. A lot of farmers do not go through with these tillage methods though. Farmers will usually till their soils, so they can stay away from weeds and compaction.
Another idea to improve the soil is to use cover crops. Cover crops are plants grown to improve the quality and productivity of the soil in between regular seasons. Using cover crops makes the soil more stable and can increase the underground biomass. All of this information on carbon sinks shows a more natural way to sequester carbon through plants in our ecosystems. Humans impact carbon sequestration in forests by deforestation for our own use along with farming methods in the agricultural field. When we do that, we are releasing more carbon dioxide into the atmosphere and this adds to carbon emissions. Some methods humans can do to promote carbon sequestration and improve the environment are to practice good farming methods like cover cropping and conservation tillage. In forests to improve sequestration is afforestation and forest management. Afforestation is the action of planting trees in an unforested location. Forest management looks at the methods of harvesting and looking at what can be done to improve the growth of trees. By practicing these methods, we can improve the environment by having less carbon in the air to reduce our overall emissions. This improves the natural environments around us like the Chesapeake Bay.
The bay gets a lot of sediment pollution due to farms and if they are practicing better farming methods it can help what’s going into the bay and help in the climate change crisis. Humans are becoming increasingly aware of the harm excess Carbon Dioxide in the atmosphere is and will cause. While carbon can be stored naturally through the environment, many technologies exist to capture existing carbon dioxide in the atmosphere, (or carbon that would be normally emitted) and using it or storing it elsewhere. These specific technologies are not natural and are entirely artificial. It is important to mention the distinction between Carbon Dioxide removal and reducing emissions. Carbon Dioxide removal deals with directly removing existing carbon that has already been created from human activity, rather than attempting to stop the carbon from being created in the first place. Several techniques exist that have the potential for carbon removal and sequestration, with some already being used to others still in their infancy.