Evaluation Of Carbon Emission Trend And Influencing Factors Of Livestock And Poultry Breeding In China

In recent years,a series of ecological and environmental problems caused by greenhouse gases have been widely concerned around the world.Reducing carbon emissions and actively dealing with climate change have become the common goal of people of all countries.Carbon emissions from livestock and poultry production account for 18%of man-made carbon emissions and have become an important source of global greenhouse gas emissions.China is a big country in livestock and poultry breeding.It is an important part of China to achieve the goal of"double carbon"by achieving carbon peak and carbon neutralization in livestock and poultry breeding.Identifying the current situation,spatial-temporal trend and key influencing factors of carbon emissions from livestock and poultry farming is helpful to further clarify the change law of carbon emissions from livestock and poultry farming,provide theoretical basis and decision-making support for further promoting cleaner production and improving carbon emission reduction policies in the livestock and poultry farming industry,and lay a foundation for the ultimate"green development"of the livestock and poultry farming industry.In this paper,based on the IPCC coefficient method,the relevant methods and given coefficients in the Guidelines for the Preparation of Provincial Greenhouse Gas Inventories（Trial）（2011）,a carbon emission accounting model for livestock and poultry farming was established to evaluate the current situation of carbon emissions from livestock and poultry farming in China from 1980 to 2020.Based on regression analysis method and trend analysis method,the time trend of total carbon emission was analyzed.Based on the provincial scale,the distribution difference,autocorrelation,heterogeneity and convergence of carbon emissions from livestock and poultry farming were analyzed from the spatial dimension.Finally,the influencing factors of carbon emissions from livestock and poultry farming were identified,and the changing trends of relevant influencing factors and their impacts on carbon emissions under different scenarios were analyzed.The main research results and conclusions of this paper are as follows.（1）From 1980 to 2020,the total carbon emissions from livestock and poultry farming in China showed certain stage characteristics.The first stage was the period from 1980 to2004,the total carbon emission of livestock and poultry production fluctuated and increased.It was 402.1 million tons of CO₂e in 1980 and 673.5 million tons of CO₂e in 2004,an increase of nearly 67.5%,with an average annual growth rate of 2.2%.In the second stage,from 2005 to 2007,the total carbon emissions from livestock and poultry production decreased rapidly from 653.0 million tons of CO₂e to 526.0 million tons of CO₂e,a decrease of 19.4%.In the third stage from 2008 to 2020,carbon emissions from livestock and poultry farming in China fluctuated and increased again,reaching 426.6 million tons of CO₂e in2008 and 506.3 million tons of CO₂e in 2020,with an increase of 18.7%and an average annual growth rate of 1.4%.On the whole,the total carbon emission of livestock and poultry production in China is not simply monotonously increasing or decreasing.（2）In terms of the contribution of different greenhouse gases to carbon emissions,the contribution ratio of CH₄ emission is 48.2%～61.2%,the contribution ratio of N₂O emission is 8.8%～13.3%,and the contribution ratio of CO₂ emission is 26.4%～43%.In terms of the contribution of different livestock and poultry breeds to carbon emissions,beef cattle,cows,goats,sheep,camels and other ruminants accounted for a large proportion of emissions,averaging 57.7%over the years.The proportion of carbon emissions of goats,sheep,poultry and pigs showed a slow rising trend,while the proportion of carbon emissions of dairy cows,beef cattle,horses,donkeys,mules and camels showed a decreasing trend year by year.From the perspective of the contribution of provinces,the carbon emissions from livestock and poultry farming in Shandong Province,Sichuan Province,Henan Province,Inner Mongolia Autonomous Region,Guangdong Province and Hebei Province accounted for 36.7%to 43.8%.As a result,the carbon emission intensity of unit protein production showed a downward trend year by year,from 89.1 million tons of CO₂e/10,000 tons of protein in 1980 to 10.8 million tons of CO₂e/10,000 tons of protein in 2020,a decrease of87.9%.CH₄ has the highest carbon emission intensity,from 50.9 million tons of CO₂e/10,000 tons of protein in 1980 to 7.1 million tons of CO₂e/10,000 tons of protein in2020.（3）The results of regression model showed that carbon emissions from livestock and poultry farming in China tended to change over time from 1980 to 2020.With the increase of time t,carbon emission showed an"N-shaped"curve trend,that is,it first increased,then decreased and then increased with time.The results of Mann-Kendall test show that the trend of carbon emissions from livestock and poultry production is stable.In the period from 1980 to 2004 and from 2008 to 2020,the upward trend is significant,but the rate of increase is different,and the rise is slower in the latter period.The carbon emissions of livestock and poultry farming differ significantly between provinces,and the ratio between the provinces with the highest emissions and the provinces with the lowest emissions ranges from 19.2 to 101.6 times.The spatial heterogeneity andσconvergence andβconvergence analysis of carbon emissions from livestock and poultry farming show that the gap of carbon emissions from livestock and poultry farming is decreasing,but the narrowing range and speed are slow,and it takes a long time to reach a stable development.The spatial autocorrelation and spatial aggregation of carbon emissions from livestock and poultry farming were weak.（4）Population density,per capita income and livestock and poultry industry structure have important effects on livestock and poultry carbon emissions.According to EKC model test,there is an"N"curve relationship between per capita income and carbon emissions from livestock and poultry farming.In this paper,we set four different scenarios based on population density,per capita income and livestock and poultry industry structure.The STIRPAT model shows that carbon emissions from livestock and poultry production under each scenario have shown a downward trend in the predicted year.When the population is developing at a high speed and the industrial structure and per capita income are developing at a low speed,the carbon emission of livestock and poultry farming is the largest,reaching513.6 million tons of CO₂e in 2030 and 497.54 million tons of CO₂e in 2035.When the population is developing at a low speed and the industrial structure and per capita income are both developing at a high speed,the carbon emissions from livestock and poultry farming are the lowest,reaching 464.7 million tons of CO₂e in 2030 and 426.1 million tons of CO₂e in 2035.