Sustainability Assessment And Low-carbon Regulation Strategy Of Land Use Carbon Environment

The climate change caused by global warming is continually destroying the earth’s ecological balance.Climate disasters such as drought,flood,El Ni(?)o,glaciers melting and sea level rise have become serious challenges for sustainable development that the society can’t escape from,thus controlling the greenhouse effect and reducing the instability of the climate brought about by global warming has become a research hotspot of political and academic circles.As an potential driver of global warming,carbon emission has become the research focus of global climate change since the 1990 s.Scholars in related fields have different focuses on carbon emission accounting,the impact of land use on carbon emission,carbon simulation and carbon reduction strategies.As the main source and concentrated area of carbon emission,the carbon cycling research has been paid much attention by many scholars since the beginning of this century.The research of carbon emission and reduction based on the perspective of urban land use has become an important research topic for realizing efficient and low-carbon urban land utilization,promoting sustainability of development as well as being a breakthrough direction for urban carbon management.At present,the academia has accumulated rich results in the above research fields,and has formed a complementary status quo in the content.Foreign scholars made a analysis from the microscopic perspective of soil carbon and vegetation carbon,measuring the carbon flux changes brought about by land use change.From the medium perspective,they Conducted a comprehensive study of greenhouse gas and made a interaction research between land use carbon emission and other factors.From the macro perspective,they analyzed the land use carbon reduction strategy,the advantages and disadvantages of replacement from biofuels to fossil energy and the impact of biofuels on the environment,etc.,paying more attention to the carbon release and impact mechanism,measuring the natural and anthropogenic carbon and analyzing influencing factors of the emission change,thus to propose countermeasures to reduce carbon flux.Domestic research reflected the comprehensive and interdisciplinary of land use and carbon emission,but the theoretical application and research focus were different.Based on the macroscopic perspective,most scholars took the estimation of the impact of land use change on vegetation and soil carbon storage in terrestrial ecosystem as the research basis to analysis regional spatial difference of terrestrial ecosystem carbon sinks/sources.From the medium to micro perspective,it paid more attention to the recognition and measurement of land use and agricultural carbon emission,carbon accumulation changes in special areas and soil carbon accounting.At the research field of carbon emission reduction,scholars usually analyzed the impact of land use structure and energy consumption on carbon emission at the level of province and city based on the government’s commitment of carbon reduction,and conducted research from the perspectives of urban land use,planning and management.The above-mentioned researches provide a good theoretical basis for land use carbon emission and carbon reduction,but still face some practical problems,for example how to evaluate the necessity of carbon emission reduction at regional level,how to strengthen the pertinence of carbon reduction and how to improve the effectiveness of carbon reduction in land use?Based on the above considerations,this paper carries out the analysis of carbon footprint and carbon carrying capacity of urban land use based on the theory of ecological footprint,and evaluates the sustainability of carbon environment.Taking carbon footprint as an unexpected output,we explore the carbon efficiency of land use structure as well as the carbon efficiency of land intensive utilization by building a super-efficient SBM model,thus to control major directions of carbon reduction in land use macroscopically.By discussing the relationship between construction land and carbon footprint expansion through environmental Kuznets curve validation and decoupling analysis,making driving factor decomposition with KAYA identity and LMDI model,it finally carries out path analysis of emission reduction on industrial land and traffic land.The main research content and conclusion of this paper are as follows:(1)This chapter identifies the basic models for carbon footprint measurement and sustainability assessment so that to provide data support for the analysis below.Based on the “2006 IPCC guidelines for national greenhouse gas inventories” and domestic and international research,the carbon emission and carbon sink calculation models for different types of land use are sorted out.From the perspective of ecological footprint and the current situation of land use in Wuhan,this part improves the carbon footprint model and the carbon deficit model consisted of ecological implications with incorporating the socio-economic development and human survival need into the calculation process,which enhances its practical significance.Finally,it defines a carbon environmental pressure model based on the above model to quantify the sustainability of the current urban carbon environment.(2)This chapter calculates the carbon emission,carbon sink,carbon footprint,carbon carrying capacity and carbon deficit of Wuhan City from 1996 to 2016,quantifying the overall carbon environment and sustainability of Wuhan.The results show that both carbon emission and carbon sink show an increasing trend and net carbon emission shows an “S”-type fluctuation trend,in which carbon emission is more obvious than carbon sink;Carbon footprint expansion is similar to carbon emission,but the carbon carrying capacity is decreasing year by year.The comparative analysis of land use shows that the total carbon footprint of construction land is the largest and the rising trend is remarkable.Among them,industrial carbon emission accounts for the highest proportion,while the carbon emission from public business service and transportation increase the most and the residential carbon is generally stable.The carbon emission of agricultural land increases first and then decreases.Since the carbon carrying capacity of land depends on the production of cultivated land,the invasion of cultivated land by urban expansion is an important reason for the decline of carbon carrying capacity.The remaining carbon sinks provide a lower proportion of carbon carrying capacity,however the increase of carbon carrying capacity in urban green space indicates that the protection of carbon sink has a positive effect on improving urban carbon carrying capacity.The carbon deficit level in Wuhan shows a staged upward trend and it is currently at an uncontrollable high-risk level.The result of improved carbon footprint model still shows that the carbon environment in Wuhan is in a serious deficit.Environmental pressure continues to increase so that the controls of urban carbon deficit level has to be strengthened.(3)This chapter calculates the carbon efficiency of urban land structure and the carbon efficiency of land intensive utilization during the study period,and it also analyzes the efficiency development trend,the input improvement results as well as the intrinsic reasons for inefficiency so that the macro direction of low-carbon regulation of land use is clarified.The carbon efficiency of the land structure in Wuhan experienced a phased feature of steady tendency-sudden drop-slow rise,and the comprehensive efficiency does not reach its full effective state.Insufficient scale efficiency caused by inadequate carbon sink and redundant carbon source is the main reason for the reduction of carbon efficiency of land structure;Both the intensive utilization of agricultural land and construction land show an upward trend,while the carbon efficiencies of land intensive utilization do not show a single growth trend.The carbon efficiency of agricultural land intensive utilization is characterized by a U-shaped change from having(super)efficiency to weak efficiency and then increasing to effective state,which indicates that the agricultural land use and carbon efficiency are gradually coordinated.The direction of input-output improvement values is consistent with the trend of factors’ growth,indicating that the carbon efficiency will continue to improve in the future.The carbon efficiency of construction land intensive utilization declines in logarithmic form,technology and scale efficiency are the reasons for the decline of its comprehensive efficiency.However,redundancy of per capita labor force,per capita energy and per capita fixed asset investment and insufficient technology investment are the main reasons for the weak efficiency in the latter period,which is essentially unreasonable in urban economic structure,social production and living patterns of residents.Therefore,in addition to protecting cultivated land and preventing the blind expansion of construction land,rational construction land use is needed for enhancing the carbon efficiency.(4)In view of the impact of construction land expansion and insufficient carbon efficiency on carbon deficit,this chapter uses environmental Kuznets curve and decoupling theory to validate the relationship between carbon footprint and internal types of construction land,clarifying the future direction of carbon reduction for land utilization.The EKC result indicates that there is an inverted “U” type EKC relationship between the total amount of construction land and the carbon footprint,but the construction land has not yet expanded to the inflection point.Except for industrial land,other types of construction land do not conform to the typical EKC curve shape,the carbon footprint of residential land is generally stable,while the marginal carbon growth rate of land for transportation and public commerce is extremely high;The results of the decoupling also indicate that the carbon footprint is relatively decoupled from the expansion of industrial land and residential land,while the public commerce land and transportation land are generally characterized by expansion negative decoupling.Therefore,the utilization of transportation land and public commerce land will be the key direction for controlling expansion of carbon footprint in the future,industrial land is still an important type of land for reducing carbon footprint because of its large proportion,and residential land is not an efficient way to achieve low-carbon management and regulation.(5)In this chapter,the author decomposes the driving factors of carbon footprint of the main land and then analyses the ways of reducing emission of industrial land and traffic land according to the decomposition results.It can be seen that controlling the scale of industrial land,improving energy efficiency and industrial structure are important ways to control the excessive growth of industrial carbon footprint in the future,residential carbon footprint should be controlled with reducing the overall energy consumption and emission per unit of household energy consumption,while traffic land should focus on adjusting traffic structure and optimizing transportation energy structure.Based on the above conclusions,the paper analyzes the carbon reduction pathways for industrial and transportation land respectively.First,it proposes ideas of controlling land size and carbon emission intensity for industrial land,putting forward four land regulation directions for major industries,including encouraging development,free development,prudent development,industrial upgrading or reducing industrial scale.It also proposes the basic development ideas of industrial land supplying principle for enrichment in category I,lowcarbon in category II,differential development in category III and refined simplification in category IV.In addition,it suggests for 80%,60% and 30% of emission intensity being short-term,medium-term and long-term control targets for land supply and utilization in the meaning time.For traffic land,the analysis of traffic carbon emission trends and per capita carbon emission intensity trends reveals that the direction of changing traffic structure should be encouraging subways and ground public transportation as well as reducing urban vehicle travel demand.At the end of the chapter,combined with the regression results of the impact characteristics on residents’ choice of travel modes,the author puts forward the carbon reduction strategy of traffic land from three aspects: urban space optimization,public transportation design optimization and traffic guidance policy.Finally,combined with the conclusions of this paper,the thesis summarizes the implications of urban low-carbon land use policy from three aspects: regulating land structure,making full use of urban carbon sink resources and controlling the carbon footprint of construction land.Simultaneously,it prospects for future research directions.