Radiocarbon isotope technique as a powerful tool in tracking anthropogenic emissions of carbonaceous air pollutants and greenhouse gases: A review

Air pollution and climate change are two important threats facing in our planet and are tightly linked to carbonaceous components in the atmosphere. A better understanding of the emission sources and environmental fate/sink of carbonaceous components is critical for improving our knowledge of the global carbon cycle and mitigating the negative environmental impacts of air pollution and climate change on human well-being. Radiocarbon (14C), which is decayed completely in fossil fuel (e.g. coal and petroleum), is an ideal tool for quantifying the carbon flow in various carbon reservoirs. This study reviews the current knowledge of 14C in organic carbon (OC), elemental carbon (EC), individual organic compounds, methane (CH4), carbon dioxide (CO2), annual plants, and tree rings. The impacts of fossil and non-fossil sources on the atmosphere can be quantified by measuring 14C. We also report on the influence of nuclear power plants and sea-air gas exchange on the abundance of 14C in the atmosphere. The increasing fossil fuel emissions indicated by the depletion of 14CO2 under IPCC RCP scenarios, support the urgent need to devise ambitious strategies of reducing carbonaceous components to achieve sustainable development on Earth. This review summarizes the challenges and perspectives of 14C studies of the atmosphere.