Evolutionary Characteristics Of Carbon Emissions In The Central City Of Changchun And The Design Of Community Carbon Reduction Units

Since the industrial revolution,human activities have consumed a large amount of fossil energy,mainly coal and oil,resulting in an excessive amount of carbon dioxide being emitted into the atmosphere,the greenhouse effect is increasing year by year,and global warming has brought about a number of negative effects,for which China has proposed the double carbon target of achieving carbon peaking by 2030 and carbon neutrality by 2060.The current dual pressure on China at home and abroad has the urgent need to reduce carbon development.The Second Tenth Congress has once again made it clear that we must actively and steadily promote the achievement of peak carbon and carbon neutrality and further decompose the emission reduction targets into local administrative units.As the main source of carbon emissions in cold regions,cities are characterised by high carbon emissions and low carbon sinks due to seasonal factors,and higher carbon emissions for the same amount of economic output.Therefore,in the construction of China’s dual carbon target,it is important to clarify the carbon emission characteristics of cold cities and their influencing factors for the early achievement of the dual carbon development target.The study focuses on the translation and estimation of urban carbon emissions,spatial and temporal evolution characteristics,analysis of influencing factors and the design of carbon reduction units,taking the central city of Changchun as an example.The method of carbon emission estimation using direct nighttime lighting data has the problem of distortion of the results of industrial land,so the method of translating nighttime lighting data coupled with construction land is proposed.A pilot carbon reduction unit is identified in the central city of Changchun,and a suitable planning strategy for the carbon reduction unit is proposed and a specific planning plan is given under the guidance of carbon reduction.Based on this study,the spatial and temporal evolution characteristics of annual and seasonal carbon emissions in the central city of Changchun from 2012 to 2021 and the related influencing factors were summarized,and the Xikang Road community was used as an example to design a carbon reduction unit.The main conclusions are:(1)the new method based on the coupling of urban construction land and nighttime lighting data can effectively improve the accuracy of urban carbon emission identification results;(2)annual carbon emissions as a whole fluctuate in growth,slowly decreasing in summer and rapidly increasing in winter,with carbon emissions in winter being 1.83 times higher than those in summer;(3)the distribution of carbon emissions has obvious spatial autocorrelation,and the annual distribution of high-high clusters has obvious spatial autocorrelation,with the annual distribution of high-high clusters characterized by contraction at the periphery and aggregation at the centre,expanding outward along the rail transit in summer while aggregating towards the centre of the new district in winter,and the annual distribution of low-low clusters shifting from centralized to decentralized,with a small expansion in summer and a large contraction in winter,in which the influence of residential land use on both high and low spatial aggregation has increased;(4)The main factors influencing annual carbon emissions are,in order,economic level > energy endowment > urban construction;urban construction >economic level > environmental climate in summer,and economic level > urban construction > environmental climate in winter,with the government ignoring the climatic characteristics of cold-land cities when formulating relevant policies.(5)For the design of the Xikang Road community carbon reduction unit,five design strategies are proposed for the warm building and neighbourhood,humanized slow walking system,clean energy use,intensive and efficient circulation system and cold-resistant blue-green space pattern,and the carbon reduction design is carried out in five aspects:building layout,road network transportation,energy use,resource circulation and green space system,and three levels of national-local-community protection are proposed The policy is to improve the realisability of the design of community carbon reduction units.