Simulation Study On The Scenario Of Agricultural Carbon Emission Reduction Policy Under The "Dual Carbon" Goal In China

Climate change has become one of the most serious challenges facing the current economy and society,and poses a serious threat to human survival and development.As a basic industry,agriculture is the second largest source of global carbon emissions.The global warming caused by agricultural carbon emissions cannot be ignored.In order to curb the trend of global warming,it is of great significance to explore the dynamic evolution law of agricultural carbon emissions in China to promote the realization of carbon peak and carbon neutrality.Under the background of carbon peak and carbon neutrality,based on the perspective of system theory,this paper constructs a system dynamics model of planting-stockbreeding-energy consumption-land use-environment(carbon emissions),simulates China’s agricultural carbon emissions system from 2007 to 2017 with VENSIM PLE software,and selects different policy scenarios for system simulation of the model that passed the applicability test in 2018-2060,So as to explore the dynamic evolution of agricultural carbon emissions.The following conclusions are drawn:1.Research based on system simulation.For the planting subsystem,chemical fertilizer and rice planting carbon emissions are the main carbon sources,accounting for 42.3% and 40.4% respectively.For the animal husbandry subsystem,on the whole,the carbon emissions generated by the gastrointestinal fermentation of livestock and poultry are higher than that of manure management.Among the carbon emissions from gastrointestinal fermentation of livestock and poultry,non-dairy cows accounted for the largest proportion,accounting for 54.1% on average;On the contrary,the carbon emission of pig manure management is higher than that of gastrointestinal fermentation,and accounts for about half of the total carbon source of livestock and poultry manure management.For the carbon emission system of agricultural energy consumption,the use of thermal power such as irrigation consumes higher agricultural energy and accounts for the highest proportion of carbon emissions(47.8%).Due to the promotion of basic good farmland protection policy,the carbon source of cultivated land fluctuates little.As the main contributor of carbon sink,forest land absorbs nearly 80% of greenhouse gases.The soil organic carbon pool of cultivated land is the most active carbon pool in the terrestrial ecosystem which can be moderately adjusted in a short time.At the same time,China’s grassland carbon sink resources are abundant,making China’s carbon sink system more diverse.2.Research based on system simulation.(1)The comprehensive scenario of multipolicy coordination is the best plan for agricultural carbon emission reduction.Among the high,medium,and low adjustment policies,the medium plan has more ideal emission reduction effect and is more feasible to implement;(2)The carbon emissions of the high,medium and low schemes in 2060 are 19.19%-53.18% lower than that of the baseline scenario,of which the carbon peak will occur in 2031 under the medium scheme,with the emissions of 1.112 billion tons.At the same time,the increase of carbon sink in the ecosystem will generate more carbon balance.Under the medium plan,the net absorption of 700 million tons of carbon dioxide equivalent can make greater contributions to emission reduction in other fields.3.Research based on carbon emission intensity.The overall carbon emission intensity of the agricultural system shows a downward trend,while its rate of change is flat year by year,indicating that the agricultural carbon emission efficiency has been enhanced to a certain extent,and the implementation effect of emission reduction measures has a trend of diminishing marginal benefits.Based on the above conclusions,this paper puts forward the following countermeasures and suggestions to help achieve the dual-carbon goal: Improve the fertilization method and improve the rice planting technology;Improve feed quality,optimize feeding methods,utilize livestock and poultry manure as resources,and reduce liquid storage through drying treatment;Improve energy utilization efficiency and accelerate the promotion of green technology innovation;Strengthen land management and coordinate the integrated protection and treatment of “mountains,rivers,forests,fields,lakes,grass and sand”.