Human activities emit a large amount of fossil source CO 2, is currently atmospheric CO 2The main reason for the increase in concentration is that about 70% of the fossil source CO 2Emissions occur in cities, so the fossil source of urban CO 2The understanding of emission characteristics can provide key scientific basis for formulating carbon emission reduction policies, assessing emission reduction effects, and serving the development of low-carbon economy.
Academician of the Chinese Academy of Sciences, researcher Zhou Weijian and his team at the Institute of Earth Environment of the Chinese Academy of Sciences conducted an early use of 14C to monitor the city's atmospheric fossil source CO. 2Research. Recently, Zhou Weijian’s team performed atmospheric CO in different regions of Xi’an based on previous work. 2Continuous observation for a long time, and for the first time combined with two carbon isotope tracer methods of Δ14C and δ13C to reveal the urban fossil source CO 2Changes in the characteristics of the source and sink of the region and the season. The study found that the fossil source of winter in Xi’an 2Emissions to new atmospheric CO 2 The average contribution of (total concentration minus background concentration) is 61.8±10.6% and 57.4±9.7% in urban and suburban areas, respectively, of which coal is the main source; In summer, due to soil respiration, plant photosynthesis and other factors Impact, Fossil Source CO 2The average contribution is higher than that in winter, and it shows a pattern of regional change that is contrary to winter, ie, suburban area (90.0±24.8%) is greater than urban area (82.5±23.8%). This result shows that reducing coal consumption still reduces urban carbon emissions. An important approach, while biological emissions are also non-negligible factors, as processes such as biomass combustion and organic matter decomposition make it to atmospheric CO in winter 2The contribution can reach 40%, and in summer due to the increase of plant photosynthesis intensity, biological activities can play a carbon sink role in the urban carbon cycle. Based on this, the study believes that the future development of carbon emission reduction policies should fully consider the biological emissions to the urban atmosphere. CO 2Contributions.
The relevant research results were published on the Science of the Total Environment based on the measurements of carbon dioxide concentration, △14C and δ13C. The study was awarded by the National Natural Science Foundation of China, Chinese Academy of Sciences. And funding from the Ministry of Environmental Protection.
Winter and summer CO 2Ff Adding atmospheric CO 2Ratio (left) and Miller-Tans regression analysis results, slopes indicate atmospheric CO 2The δ13C isotopic characteristics of emission sources
