Spatial distribution of fossil fuel derived CO2 over India using radiocarbon measurements in crop plants

• Published in: Journal of environmental sciences (China) 2023-02, Vol.124, p.19-30
• Main Authors: Sharma, Rajveer, Kunchala, Ravi Kumar, Ojha, Sunil, Kumar, Pankaj, Gargari, Satinath, Chopra, Sundeep
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Crop plants; Fossil fuel CO2; Radiocarbon measurements
• ISSN: 1001-0742; 1878-7320
• DOI: 10.1016/j.jes.2021.11.003

•Spatial distribution of CO2ff and Δ14C across India using crop plants have been studied.•Δ14C values in the year 2017 are ranging from 29.33‰ to -34.06‰ across India.•CO2ff mole fractions are varying from 4.85 ppm to 26.59 ppm across India in the year 2017.•Sampling of storage organs in place of leaves in crop plants can induce a difference of 2.30 ppm in CO2ff values.•Radiocarbon in crop plant can be utilized in India to asses the CO2ff emissions in the absense of proper monitoring stations. Examining the contribution of fossil fuel CO2 to the total CO2 changes in the atmosphere is of primary concern due to its alarming levels of fossil fuel emissions over the globe, specifically developing countries. Atmospheric radiocarbon represents an important observational constraint and utilized to trace fossil fuel derived CO2 (CO2ff) in the atmosphere. For the first time, we have presented a detailed analysis on the spatial distribution of fossil fuel derived CO2 (CO2ff) over India using radiocarbon (Δ14C) measurements during three-year period. Analysis shows that the Δ14C values are varying between 29.33‰ to -34.06‰ across India in the year 2017, where highest value belongs to a location from Gujarat while lowest value belongs to a location from Chhattisgarh. Based on the Δ14C patterns, spatial distributions of CO2ff mole fractions have been determined over India and the calculated values of CO2ff mole fractions are varying between 4.85 ppm to 26.59 ppm across India. It is also noticed that the highest CO2ff mole fraction is observed as 26.59 ppm from a site in Chhattisgarh. CO2ff mole fraction values from four high altitude sites are found to be varied between 4.85 ppm to 14.87 ppm. Effect of sampling different crop plants from the same growing season and different crop plant organs (grains, leaves, stems) on the Δ14C and CO2ff have been studied. Annual and intra seasonal variations in the Δ14C and CO2ff mole fractions have also been analyzed from a rural location (Dholpur, Rajasthan). [Display omitted] .