We live in a period where the basic resources we require for life increase in scarcity, especially resources of energy, thus the race to discover and utilize new energy resources increases in competition. The industrial revolution brought about the accelerated use of fossil fuels for developmental activity and manufacturing of goods globally, and its continued use to this day has resulted in a huge emission of greenhouse gases that contribute to global warming. Being the increasingly concerning conundrum it is, global warming has been a hot potato due to the global climate change that it causes, primarily due to carbon emissions, resulting in elevated levels of carbon dioxide gas (CO2) in the atmosphere. While other greenhouse gases exist, CO2 remains the greatest contributor to global warming, due to its long lifetime in the atmosphere and its constant production as a result of human activity, such as burning fossil fuels for energy.
Several movements to transition to more renewable and “green” energy resources are driven by activists and environmentalists alike, due to the 750 billion metric tons of glacial ice that melts every year, the irreversible changes to ecosystems due to climate changes, the changes in atmospheric circulation globally, the projected 11 inches of sea level rise and 1.5 ◦C increase in global temperature 2050, which all herald a global catastrophe due to global warming.1 The current infrastructure for providing essentials, such as energy generation, manufacture of goods, food production and transport unfortunately heavily relies on technologies that result in the emission of greenhouse gases into the atmosphere, and additionally anthropogenic activity often requires deforestation and landscaping, removing one of Earth’s natural carbon capture methods, trees – making global warming a persistent issue for every being on the planet.
Since most global systems are so heavily reliant on methods that result in a net greenhouse gas emission, it is also exceedingly challenging to substitute in “cleaner” methods on a global scale. While such efforts are still being valiantly made, scientists have also conducted several studies involving the removal of major greenhouse gases from the atmosphere in areas with elevated levels of them, effectively reversing the adversity of global warming. While we know that plants and trees perform this very function through photosynthesis, a more accessible, practical, and fast-acting approach is in the works, and it comes in the form of microbes.2
Carbon-sequestering microorganisms such as algae, archaea and cyanobacteria are being looked into as viable biological CO2 capture methods, due to them being an effective means of long-term storage of CO2 to mitigate and circumvent climate change and global warming. These microbes are particularly useful as their own biological processes and metabolism naturally lead to interactions with atmospheric CO2. The extensive use of fossil fuels such as oil, coal, and natural gas by modern society raises a question on the management of natural resources and achieving sustainable development while minimizing adverse environmental impact. The biorefinery industry is an answer to this question, as it is a sector that utilizes microorganisms in renewable raw materials such as biomass to produce energy and several daily-use commodities sustainably and cost-effectively. The microorganisms involved in this industry utilize CO2 for their biological processes that create these products, thus sequestering them out of the atmosphere, while additionally creating more useful, “green” material for human use.
Studies have been done on the several biological pathways and the involvement of enzymes in the effectivity of capturing CO2 from the atmosphere, and one of the most promising findings is the several potential applications of the microorganism byproducts. These byproducts are environmentally friendly, and significantly value-added products such as biodiesel, bioplastics, extracellular polymeric substances (EPS), biosurfactants and other related biomaterials.
Biodiesel is a particular product that has sparked discussion among industry experts and scientists as a potential alternative to fossil-fuels as a renewable energy resource. It is typically produced from natural renewable resources such as fungi and microorganisms such as blue green algae and bacteria. Biodiesel does not contribute to atmospheric CO2 emission as it is biogenic, and it additionally reduces the emission of soot, sulfur, unburned hydrocarbons, and polycyclic aromatic hydrocarbons in comparison to conventional energy sources, resulting in less environmental pollution in addition to being carbon neutral. It also has a lower toxicity effect, is biodegradable, and its use is projected to reduce CO2 emissions by up to 78%. It is due to these advantages that several methods are being explored to synthesize biodiesel on a large scale.3
Another vitally important procedure through carbon capture involves the production of calcium carbonate minerals such as calcite, a mineral significant to nature. Several microbial strains, which are able to calcify and precipitate calcite have been wildly distributed in the nature, such as several cyanobacteria, eukaryotic microalgae and sulphate reducing bacteria. Calcite and other minerals of calcium carbonate are additionally very useful to human society, primarily in construction, agriculture, medicine and the chemical industry.4
In summary, carbon-sequestering microbes not only capture CO2 from the atmosphere, thus reverting greenhouse gas levels to normal and mitigating global warming – they additionally provide value added products, including a greener, pollutant-free and renewable source of energy, through natural, biological methods, resulting in a sustainable, cost-effective and active response against rising global temperatures and CO2levels in the atmosphere while advancing other useful industries in human society.5
It must be stated that with the current scientific evidence, a strong case is being made for the global implementation of biological carbon-capture methods involving microbes, especially in countries where the transition to alternative clean energy sources such as wind, nuclear and solar energy is less viable. The fate of this scientific marvel, however, rests in the hands of the people in power – governments, politicians and community leaders yet conclusively, it can be stated that the allocation of resources to further studies in this regard, and the implementation of the foundations of such carbon capture methods is in most eyes, a crucial step in reversing global warming and its resulting adversities, lest it be too late, as a result of us doing too little.
References
- Son, J. H., & Seo, K. H. (2016). Hadley Circulation Strength Change in Response to Global Warming: Statistics of Good Models. Atmosphere, 26(4), 665-672.
- Maheshwari, N., Thakur, I.S. & Srivastava, S. Role of carbon-dioxide sequestering bacteria for clean air environment and prospective production of biomaterials: a sustainable approach. Environ Sci Pollut Res 29, 38950–38971 (2022). https://doi.org/10.1007/s11356-022-19393-7
- Kumar, Manish, et al., Carbon Dioxide Capture, Storage and Production of Biofuel and Biomaterials by Bacteria: A Review.” Bioresource Technology, vol. 247, 1 Jan, 2018, pp. 1059–1068
- Sundaram, S., & Thakur, I. S. (2018). Induction of calcite precipitation through heightened production of extracellular carbonic anhydrase by CO2 sequestering bacteria. Bioresource technology, 253, 368-371.
- Ahmed, A. A. Q., Odelade, K. A., & Babalola, O. O. (2019). Microbial inoculants for improving carbon sequestration in agroecosystems to mitigate climate change. Handbook of climate change resilience, 1-21.