Impact of Elevated CO2 and Temperature on Greenhouse Gas Emission and Decomposition

Greenhouse gases (GHGs) significantly contribute to climate change by trapping heat in the Earth's atmosphere. However, anthropogenic activities, such as burning fossil fuels (coal, oil, and natural gas), deforestation, and industrial processes, have increased the concentration of these gases in the atmosphere, leading to an enhanced greenhouse effect. Agricultural operations are a major source of anthropogenic GHGs comprising CO2, CH4, and N2O, accounting for 20% of annual atmospheric change worldwide. In terms of GHG net flow, agricultural soils’ ability to be a source, sink, or neutral is mostly controlled by management practices. The combined effects of elevated CO2 and temperature result in an increase in methanogenic archaea that control CH4 emissions, which is primarily quantified by the availability of carbon. Elevated CO2 also resulted in a significant increase of N2O emissions in nitrogen-fertilized crops. Due to their significant role in biogeochemical nutrient cycling, soil microbes may have a vital role in the alteration of diversity, abundance, and functional properties of the whole soil microbiome. Interactions between soil carbon and soil organic carbon storage capacity affect microbial decomposition. Furthermore, changes in soil microenvironments caused by elevated CO2 could have long-term consequences on terrestrial biogeochemical cycles and climate change. There is a need for more research on the influence of various associated mitigating techniques on the agricultural carbon and nitrogen cycles. The present chapter emphasizes the impact of elevated CO2 and temperature on greenhouse gas emissions and decomposition in soil ecosystems.