Climate Change

The impact of greenhouse gases on earth’s radiation budget, leading to climate change

Throughout history, the earth’s climate has changed, with several pieces of evidence to indicate so. For instance, in the past 6 centuries, the earth has experienced a series of glacial retreat and advance, the last ice age ten decades ago signifying the start of the modern era of climate change (Ramswamy et al, 2006). According to Westerhold et al (2020), a significant portion of these changes are attributable to small orbital changes that lead to a change in the quantity of solar energy reaching the earth. However, the current trend of global warming is of great significance because most of it (95%) is attributable to human activity, and the trend is expected to proceed at an unprecedented state.

Through the anthropogenic greenhouse gas emissions, greenhouse gases and the heat-trapping carbon dioxide were evidenced long ago – in the 19th century (Schuumans 2021). According to Ueyama et al (2021), the greenhouse gases’ interference with the inferred energy transfer through the atmosphere has been the subject of many space explorers’ (e.g NASA) scientific expeditions, revealing several compelling pieces of evidence that the earth’s climate has changed.

The rapid global temperature rise change is the first evidence of climate. According to Holmberg et al (2021), the earth’s surface average temperature has risen to about 1.18 degrees Celsius since the 19th century, a change that is said to have been driven by increased atmospheric carbon dioxide emissions courtesy of human activity (Kumar et al, 2021). Evidence by Global Climate Change (2021) further indicates that the years between 2016 and 2020 were considered to have recorded the warmest years.

The other vital sign of the earth’s changing climate is the warming ocean. According to Levitus et al (2017), the ocean has absorbed a significant portion of the heat with the top 328 feet of the ocean indicating an increase in temperature of about 0.33 degrees Celsius since 1969. That said, it is important to note that the ocean stores at least 90% of the earth’s extra energy.

Apart from warming oceans, the other sign of climate change is the shrinking ice, especially in Antarctica and Greenland. According to Levitus et al (2017), there has been a decrease in mass of Antarctica and Greenland’s ice sheets, with data from NASA’s Gravity Recovery and Climate Experiment showing that Antarctica has lost about 148 billion tons of ice yearly while an average of 279 billion tons of ice was lost by Greenland yearly.

Upon exploring the pieces of evidence of climate change due to greenhouse gas emissions, scientists have embarked on a mission to understand the impact of these gases on the earth’s radiation budget (Hundertmark et al, 2021). First, there are three major greenhouse gases including methane, nitrous oxide and carbon dioxide, carbon dioxide being the main and most significant one because it accounts for most of the warming associated with human activities (Ueyama et al, 2021). Whereas it is a natural part of the earth’s gaseous composition, human activities (e.g. fossil fuel combustion) have caused an increase in the concentration of atmospheric carbon dioxide (Holmberg et al, 2021).

Collectively, the excessive emission of greenhouse gases has significantly impacted the greenhouse effect. Which significantly influences earth’s energy budget. In a perfect scenario where there is only the natural greenhouse effect, the constant re-radiation of the thermal radiation towards the ground balances the earth’s energy budget, trapping the earth through the trapped thermal energy (Kumar et al, 2021). However, increased greenhouse emissions caused by human activity have caused a shift in the earth’s energy budget, bringing it into an unbalanced state. Consequently, according to Ueyama et al (2021), it is important to understand that there is a need for a certain amount of energy to be retained due to the greenhouse effect but when that amount of retained energy is too much, it may lead to climate change and increased global temperature.

The energy budget is specifically important for many reasons. First, the greenhouse effect is the natural process through which the earth’s surface is heated through the absorption of atmospheric greenhouse gases such as carbon dioxide, water vapour and methane (Hundertmark et al, 2021). in the absence of the greenhouse effect, the earth cannot achieve an energy balanced state (Raza et al, 2021). therefore, to account for this imbalance, the earth’s temperature would reduce to a new state of equilibrium. According to Shakoor et al (2021), these new temperature levels achieved in the absence of the greenhouse effect would lead to an extremely cold earth.

Whereas the greenhouse effect is needed to achieve a bearable temperature for life on earth, additional atmospheric greenhouse gases disrupt already established energy budget, which is typically delicate (Tang et al, 2021). For example, a release of additional carbon dioxide in the atmosphere causes an increase in absorbed and re-emitted atmospheric energy (Moreno-Gutierrez et al, 2021). But because any change in the atmospheric energy balance must accounted for by a temperature change, an increase in earth’s temperature occurs to fill this gap. Because the increase of atmospheric carbon dioxide causes an increase in the effect of the greenhouse effect as well as an increase in temperature, this addition is termed as climate forcing – which typically leads to a destabilization of the earth’s temperature.

Therefore, the main reason why carbon dioxide poses so much risk to the earth’s energy budget is because it absorbs a significant amount of thermal energy (Raza et al, 2021). Shakoor et al (2021) stipulate that when more carbon dioxide is added to the atmosphere through human activity, the earth becomes more guarded from the energy passing through it, causing it to absorb more.

How the modern-day carbon cycle is currently being perturbed by anthropogenic activities

Any additional burden of carbon dioxide that adds to the atmosphere as a result of human anthropogenic activities leads to perturbations of the carbon cycle. The relationship between global warming effects and anthropogenic carbon is an indirect one (Feng et al 2021). according to Ediagbonya & Ajayi (2021), various forms of carbon is exchanged in various stores, existing in the form of either carbon ‘sources’ or carbon sinks – culminating in a complicated network of carbon interactions.

Lin et al (2021) observed that there are two forms of anthropogenic emissions namely: carbon dioxide from the burning of fossil fuels and other activities such as cement production; and carbon dioxide emissions from agricultural development and deforestation, which has been in store for several years. As per Gong et al (2021), the study of other gases and mass balance estimate reveals that the net ocean-atmosphere and land-atmosphere fluxes have become more different from zero. However, even though the carbon dioxide anthropogenic influxes between both the ocean and land and the atmosphere are just a small percentage of the gross natural fluxes, they have caused significant changes in the carbon content of reservoirs since pre-industrial times. According to Jalees et al (2021), these perturbations on the carbon cycle are the main causes of climate change because they persistently affect the atmosphere.

Historically, about 80% of the anthropogenic carbon dioxide emissions during the 18th century originated from the burning of fossil fuels, with the remaining 20% resulting from a change in land use such as deforestation (Ma et al 2021). Since then, as per Tang et al (2021), almost 45% of the combined anthropogenic carbon dioxide emissions have been retained in the atmosphere. On the same note, it is estimated that oceans have retained around 30% of the emissions, an amount that is evidenced by the increased atmospheric concentration of carbon dioxide without any significant changes in oceanic biology or circulation. The rest of the emissions have been taken up by terrestrial ecosystems through the vegetational growth, fertilizing effects of elevated carbon dioxide, and land management practices.

Research evidence by Ediagbonya & Ajayi (2021) indicates that atmospheric CH4 has also been significantly influenced by human activities such as waste management, food production and fossil fuel production. On the same note, Tang et al (2021) strongly believe that future population increase may cause an increase in CH4 emissions, due to increased agricultural and food production activities as demand for food rises. Furthermore, Peischl et al., 2015 argue that the current boom in oil and gas exploitation has shifted the focus on the oil leakage from drilling, storage and transportation of fossil fuels.

Because carbon dioxide does not significantly limit oceanic photosynthesis, anthropogenic carbon is not directly taken up by the biological pump (Jalees et al, 2021). Instead, the oceanic biological cycling of carbon may experience some changes due to high carbon dioxide concentrations through various feedbacks in response to climate change (Gong et al, 2021). however, according to Lin et al (2021), the speed with which anthropogenic carbon dioxide is effectively taken up by the ocean depends on how fast the surface waters are transported and mixed with the ocean’s inner layers. But, a significant number of anthropogenic carbon dioxide can be neutralized or buffered through the dissolution of CaCO3 from the deep sea’s surface sediments, even though this process may require many years to completely execute.

That said, an increase in atmospheric carbon dioxide concentration emanating from fossil fuels and emissions can only be considered here as a fraction of the problem. Land emissions, though, are not included in this definition as a result of the challenges involved in quantifying their effects, as well as the complication that land emissions from clearing deforestation can be compensated through regrowth after many years (Ma et al 2021). therefore, the airborne portion of the emissions is defined as the increase in atmospheric carbon dioxide as a fraction of total anthropogenic carbon dioxide emissions, including the fluxes associated with net land use. however, as per Lin et al (2021), the airborne fraction varies yearly as a result of the effect of varying land uptake.

By burning gas, coal and oil, humans are contributing to the acceleration of the part of the geological carbon cycle that transports carbon in sediments and rocks to the atmosphere (Ma et al 2021). Reports by Le Quéré et al (2018) revealed an estimated 430 ± 20 Pg C emissions by humans as carbon dioxide to the atmosphere. The same reports by Le Quéré et al., (2018) also reveal that the global fossil fuel emissions of carbon dioxide increased at a 4% rate between the year 2000 and 2012, even though the emissions growth declined by about 1% annually during the same period. In subsequent years, as noted by Le Quéré et al. (2018), the growth of carbon dioxide emissions continued with its declining trend, until 2015 when it levelled up when the emissions from fossil fuel and cement production were estimated to total 9.9 Pg C. As per Le Quéré et al (2018), this levelling off occurred despite the global economic expansion. However, in 2017, the global carbon dioxide rose again by an estimated 2% reportedly due to increased economic growth and lower prices of fossil fuels (Le Quéré et al, 2018).

Climate Feedback Process

Climate feedback processes are responsible for diminishing or amplifying the effect of any climate forcing, thereby playing a significantly important role in the insensitivity of the climate and its future state (Haywood, 2021). generally, feedback is the process by which a change in one quantity contributes to a change in the other quantity; and the change in the first quantity leads to a change in the second one (Woodard et al, 2021). therefore, positive feedback increases a change in the first quantity while negative feedback decreases it.

As earlier explained, climate forcing represents an increased atmospheric concentration of greenhouse gases. Therefore, as per Schmale et al (2021), both forcing and feedback together determine how and to which extent rapid the climate changes. That said, the major global warming positive climate feedback in is the tendency of that warming to increase the quantity of atmospheric water vapor, leading to further warming (Hock & Huss, 2021). On the other hand, the main negative feedback can be explained by Stefan-Boltzmann’s law, whereby the quantity of heat radiation from the earth into the atmosphere changes with the fourth power of the atmospheric or earth’s temperature (Spiridonov & Curic, 2021). Nonetheless, modelling and observation studies have found that there is a general net positive feedback to the warming, which can cause irreversible or abrupt effects depending on the magnitude and rate of climate change.

Positive feedback

A typical example of climate positive feedback is the carbon cycle feedback of hydrates. Also called methane hydrates, hydrates are water ice that are made up of big portions of methane (Shakirova & Huang, 2021). Large hydrates deposits have been discovered under oceanic and seafloor. Ideally, the release of large quantities of natural gas from deposits of hydrate as a result of massive global warming may have contributed to past and most probably future climate changes (Haywood, 2021). according to Hock & Huss (2021), the release of these methane hydrates is potentially a major outcome of an increased temperature by around 5 degrees Celsius in itself, because as a greenhouse gas, methane is more powerful than carbon dioxide. If this theory holds, then the amount of available atmospheric oxygen is likely to be greatly affected in future.

Negative feedback

There are a series of examples of negative feedbacks including blackbody radiation, chemical weathering and net primary productivity. In blackbody radiation, as the blackbody temperature increases, there is an increase in infrared radiation back into the atmosphere with the fourth power of its absolute temperature – at least according to Stefan-Boltzmann law (Woodard et al, 2021). As per Schmale et al (2021), this leads to an increase in the amount of outgoing radiation as temperatures in the earth increases. This negative feedback is also termed the Planck feedback (Hock & Huss, 2021).

Chemical weathering in the geological long-term leads to the removal of carbon dioxide from the atmosphere (Hock & Huss, 2021). The current global warming contributes to an increase in weathering, representing significant feedbacks between the earth surface and the climate (Woodard et al, 2021). according to Schmale et al (2021), biosequestration also contributes to the storage of carbon dioxide through various biological processes. The formation of shells by oceanic organisms over a long time removes carbon dioxide from the ocean. However, it takes thousands of years to convert carbon dioxide to limestone. Net primary productivity tends to change with an increased carbon dioxide, as plants photosynthesis increase as a result of the increase in concentrations. However, this effect is swamped by other changes that are associated with global warming.

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References

Ediagbonya, T. F., & Ajayi, S. (2021). Risk assessment and elemental quantification of

anthropogenic activities in soil. Environmental Geochemistry and Health, 1-14.

Feng, D., Fu, M., Sun, Y., Bao, W., Zhang, M., Zhang, Y., & Wu, J. (2021). How Large-

Scale Anthropogenic Activities Influence Vegetation Cover Change in China? A Review. Forests, 12(3), 320.

Global Climate Change (2021) Vital Signs of the Planet.

https://climate.nasa.gov/evidence/

Gong, X., Ding, Q., Jin, M., Zhao, Z., Zhang, L., Yao, S., & Xue, B. (2021). Recording

and response of persistent toxic substances (PTSs) in urban lake sediments to anthropogenic activities. Science of The Total Environment, 777, 145977.

Haywood, J. (2021). Atmospheric aerosols and their role in climate change. In Climate change (pp. 645-659). Elsevier

Hock, R., & Huss, M. (2021). Glaciers and climate change. In Climate Change (pp. 157- 176). Elsevier.

Holmberg, M., Akujärvi, A., Anttila, S., Autio, I., Haakana, M., Junttila, V., ... & Forsius, M. (2021). Sources and sinks of greenhouse gases in the landscape: Approach for spatially explicit estimates. Science of The Total Environment, 781, 146668

Hundertmark, W. J., Lee, M., Smith, I. A., Bang, A. H., Chen, V., Gately, C. K., ... & Hutyra, L. R. (2021). Influence of landscape management practices on urban greenhouse gas budgets. Carbon Balance and Management, 16(1), 1-12.

Jalees, M. I., Farooq, M. U., Anis, M., Hussain, G., Iqbal, A., & Saleem, S. (2021). Hydrochemistry modelling: evaluation of groundwater quality deterioration due to anthropogenic activities in Lahore, Pakistan. Environment, Development and Sustainability, 23(3), 3062-3076

Kumar, A., Thanki, A., Padhiyar, H., Singh, N. K., Pandey, S., Yadav, M., & Yu, Z. G. (2021). Greenhouse gases emission control in WWTS via potential operational strategies: A critical review. Chemosphere, 129694

Levitus, S.; Antonov, J.; Boyer, T.; Baranova, O.; Garcia, H.; Locarnini, R.; Mishonov, A.; Reagan, J.; Seidov, D.; Yarosh, E.; Zweng, M. (2017). NCEI ocean heat content, temperature anomalies, salinity anomalies, thermosteric sea level anomalies, halosteric sea level anomalies, and total steric sea level anomalies from 1955 to present calculated from in situ oceanographic subsurface profile data (NCEI Accession 0164586). Version 4.4. NOAA National Centers for Environmental Information. Dataset. doi: 10.7289/V53F4MVP https://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/index3.html

Lin, C. T., Chiu, M. C., & Kuo, M. H. (2021). Effects of anthropogenic activities on microplastics in deposit-feeders (Diptera: Chironomidae) in an urban river of Taiwan. Scientific Reports, 11(1), 1-8.

Ma, R., Li, L., & Zhang, B. (2021) Impact Assessment of Anthropogenic Activities on the Ecological Systems in the Xiongan New Area in the North China Plain. Integrated Environmental Assessment and Management

Moreno-Gutiérrez, J., & Durán-Grados, V. (2021). Calculating ships' real emissions of pollutants and greenhouse gases: Towards zero uncertainties. Science of The Total Environment, 750, 141471

Peischl, J., T. B. Ryerson, K. C. Aikin, J. A. de Gouw, J. B. Gilman, J. S. Holloway, B. M. Lerner, R. Nadkarni, J. A. Neuman, J. B. Nowak, M. Trainer, C. Warneke, and D. D. Parrish, 2015: Quantifying atmospheric methane emissions from the Haynesville, Fayetteville, and northeastern Marcellus shale gas production regions. Journal of Geophysical Research: Atmospheres, 120(5), 2119-2139, doi: 10.1002/2014jd022697

Ramaswamy et.al., (2006) Anthropogenic and Natural Influences in the Evolution of Lower Stratospheric Cooling,” Science 311 (24 February 2006), 1138-1141

Raza, S. T., Tang, J. L., Ali, Z., Yao, Z., Bah, H., Iqbal, H., & Ren, X. (2021). Ammonia Volatilization and Greenhouse Gases Emissions during Vermicomposting with Animal Manures and Biochar to Enhance Sustainability. International Journal of Environmental Research and Public Health, 18(1), 178.

Schmale, J., Zieger, P., & Ekman, A. M. (2021). Aerosols in current and future Arctic climate. Nature Climate Change, 11(2), 95-105

Shakirova, A., & Huang, Y. (2021). A Neural Network Model for Shortwave Radiative Feedback Quantification. Earth and Space Science Open Archive ESSOAr

Shakoor, A., Shahbaz, M., Farooq, T. H., Sahar, N. E., Shahzad, S. M., Altaf, M. M., & Ashraf, M. (2021). A global meta-analysis of greenhouse gases emission and crop yield under no-tillage as compared to conventional tillage. Science of The Total Environment, 750, 142299

Spiridonov, V., & Ćurić, M. (2021). Climate and Climate Change. In Fundamentals of Meteorology (pp. 377-397). Springer, Cham

Tang, K., Wang, M., & Zhou, D. (2021). Abatement potential and cost of agricultural greenhouse gases in Australian dryland farming system. Environmental Science and Pollution Research, 1-12

Tang, X., Shen, M., Zhang, Y., Zhu, D., Wang, H., Zhao, Y. and Kang, Y., 2021. The changes in antibiotic resistance genes during 86 years of the soil ripening process without anthropogenic activities. Chemosphere, 266, p.128985

Ueyama, M., Iwata, H., Kobayashi, H., Euskirchen, E., Merbold, L., Ohta, T., ... & Schuur, E. A. (2021). Greenhouse Gases and Energy Fluxes at Permafrost Zone. In Arctic Hydrology, Permafrost and Ecosystems (pp. 527-558). Springer, Cham.

eyama, M., Iwata, H., Kobayashi, H., Euskirchen, E., Merbold, L., Ohta, T., ... & Schuur, E. A. (2021). Greenhouse Gases and Energy Fluxes at Permafrost Zone. In Arctic Hydrology, Permafrost and Ecosystems (pp. 527-558). Springer, Cham

Ueyama, M., Iwata, H., Kobayashi, H., Euskirchen, E., Merbold, L., Ohta, T., ... & Schuur, E. A. (2021). Greenhouse Gases and Energy Fluxes at Permafrost Zone. In Arctic Hydrology, Permafrost and Ecosystems (pp. 527-558). Springer, Cham.

Westerhold et. al. (2020) An astronomically dated record of Earth’s climate and its predictability over the last 66 million years," Science vol. 369 (11 Sept. 2020), 1383-1387

Woodard, D. L., Shiklomanov, A. N., Kravitz, B., Hartin, C., & Bond-Lamberty, B. (2021).

A Permafrost Implementation in the Simple Carbon-Climate Model Hector. Geoscientific Model Development Discussions, 1-21.