Let's take that CO2 back to the ground
Countries where most of their energy is produced from coal are big enough to have a significant impact on the environment, such is the case of the United States and China. According to the Natural Resources Defense Council in 2006 more of the 50% of energy in the US came from coal.
It is clear that this coal energy industry is responsible for an enormous amount of CO2 emissions which are helping to accelerate the Global Warming phenomenon, and the sole idea of considering to shut down all the plants at once to stop increasing CO2 footprint is a total nonsense because that would imply to leave millions of inhabitants of these countries without access to basic services.
Thus, institutes and organisations around the world have been researching how to reduce this footprint without the inconvenience of leaving millions unattended, to avoid that a great amount of coal workers end up without their jobs and to make this energy industry a little more environment-friendly. Among these, Carbon Capture and Sequestration is the one that has proven its positive impact although it is not of immediate results.
Carbon Sequestration is a useful process to reduce the greenhouse effect due to carbon emissions by two different approaches, according to the MIT CC&ST Program: capturing carbon dioxide at its source and storing it in non-atmospheric reservoirs or by enhancing natural processes that will permit the removal of carbon dioxide from the atmosphere.
How does carbon sequestration works?
As carbon sequestration has different approaches, according to Nebraska Energy Office (2010), the different processes are categorized as biological or physical/chemical. The biological process as mentioned above, is based in the enhancement of natural processes which will allow to affect directly on the carbon cycle and remove as much carbon dioxide as possible from the atmosphere. This could be done by reforesting, creating urban foresting, improving agricultural practices, working on restoring wetlands and contributing to the phytoplankton growth by urea and iron fertilization.
The physical and chemical processes are related to biomass and the mineral carbonation. The biomass-related carbon sequestration can be done by a technology called bio-energy with carbon capture and storage in power plants thanks to CO2 interception before it is released into the atmosphere and redirected to geological storage locations, also there are other processes such as burying trees, charcoal produced by pyrolysis of biomass waste or subterranean injection into depleted oil and gas reservoirs or into the deep ocean. On the other hand, the mineral carbonation helps to reducing carbon dioxide to oxalic acid by a process of electro-catalysis of a copper complex, this process will allow to store the CO2 in stable minerals.
Sequestration and carbon capturing could help to reduce dramatically the CO2 footprint and the impact of the greenhouse effect, these processes have their downsides that are the big capital costs and the energy penalties as a consequence of the capture and sequestration parallel processes. Besides, China has only developed pilot projects of carbon sequestration which are not as massive as needed to revert the worrying amounts of carbon dioxide emissions.
It seems that there is still a long road ahead to reach a point where this technology becomes an important part of the energy production and other industrial processes that will help to meet regulations on reduction of carbon dioxide footprint and the greenhouse effect. But as long as there are no other ecological technologies dedicated to reduce CO2 emissions applied to the industries, carbon capturing and sequestration is the highest bet to slowing down global warming.