City-level range three-carbon emission accounting method and accounting model based on multi-source data

Abstract

The invention relates to the technical field of carbon emission, in particular to a city-level range three-carbon emission accounting method and system based on multi-source data, and the method comprises the following steps: 1, constructing a city-level range three-carbon emission accounting framework covering a plurality of city key materials; 2, establishing a decision tree of various key material accounting methods based on data quality grading, and providing a judgment basis and a required input data format; and step 3, calculating the three-carbon emission in the city-level range. The invention aims to solve the problems that the current urban range three-carbon emission accounting is only suitable for a few cities and three-carbon emission accounting reports in different urban ranges cannot be transversely compared, and provides a basis for enriching the current Chinese urban carbon emission accounting data and the calculation range.

Description

Technical Field

[0001] The present invention relates to the field of carbon emission technology, and in particular to a city-level scope 3 carbon emission accounting method and an accounting model based on multi-source data. Background Art

[0002] City-level Scope 3 carbon emissions refer to all other emissions that occur outside the city boundaries due to activities conducted within the city boundaries (excluding electricity and heat emissions). It is a difficult link that affects the global net zero emission process, usually involving product use and upstream supply chains. As an open and complex giant system, cities are connected to the outside world through production and consumption behaviors. City-level Scope 3 carbon emissions have become an important part of the comprehensive assessment of urban carbon footprints, which is conducive to more reasonable clarification of urban carbon responsibilities, formulation of reasonable urban emission reduction strategies, and help cities promote emission reductions across the entire supply chain during planning and development.

[0003] With the growing demand for city-level Scope 3 supply chain emissions accounting, some international organizations are committed to establishing an accounting framework to make up for the lack of international standards for city-level Scope 3 carbon emissions accounting. At present, there are two main accounting ideas for city-level Scope 3 carbon emissions. One method framework is based on the community-wide infrastructure supply chain carbon footprint accounting method, which considers the cross-border carbon emissions of key infrastructure and food supply sectors in the city. This method adopts a hybrid life cycle assessment method to multiply the use activity data with the corresponding emission factors related to the use phase and supply chain. This method relies on real and detailed use and supply data, and the use activity data mainly comes from surveys or official reported statistics. However, for most cities, it is very challenging to obtain these data. Another method framework is the consumption-based carbon footprint accounting method, which quantifies the emissions caused by end-use activities (production and consumption related to infrastructure and non-infrastructure supply sectors) within the city, and uses the environmental extended input-output model (EE-MRIO) to use output data to evaluate the consumption of different products and services in different industries. This approach relies on detailed input-output data, which are also unavailable for most cities. Summary of the invention

[0004] The present invention provides a city-level Scope 3 carbon emissions accounting method and model based on multi-source data, which can make up for the high data requirements of the existing technology and provide an accounting guide suitable for most cities.

[0005] A city-level scope 3 carbon emissions accounting method based on multi-source data according to the present invention comprises the following steps:

[0006] Step 1: Build a city-level Scope 3 carbon emissions accounting framework covering a variety of key urban materials;

[0007] Step 2: Establish a decision tree for various key material accounting methods based on data quality classification, and provide judgment basis and required input data format;

[0008] Step 3: Calculate city-level Scope 3 carbon emissions.

[0009] As a preference, the city-level Scope 3 carbon emissions accounting framework in Step 1 is established based on the following assumptions:

[0010] 1) The outward transfer volume of a city is recorded as the difference between the city's demand and supply;

[0011] 2) Products produced within the city are supplied to the local area first, and the demand gap for key materials caused by final demand behavior is transferred from outside the city to achieve a balance between supply and demand, without considering inventory issues.

[0012] As a preferred option, in the city-level Scope 3 carbon emissions accounting framework, the Scope 3 carbon emissions caused by the demand for each key material are defined as the product of its external transfer amount and the supply chain carbon emission factor, as shown in the following formula:

[0013]

[0014] Q import,i =Q demand,i -Q supply,i (2)

[0015] In the formula, CE Scope3 refers to the city-wide carbon emissions; i refers to the type of accounting materials; Q import Refers to the external adjustment amount of the i-th material; EF i is the carbon emission factor of the supply chain of the i-th material; Q demand,i is the demand for the i-th material; Q supply,i is the supply of the i-th material.

[0016] Preferably, in step 2, for each category of external investigation activity data, they are sorted from high to low in priority, and a multi-level method is set up; actual survey data is used first, and statistical data is used for estimation when survey data is missing, and then a downgraded allocation estimation method is used.

[0017] Preferably, in step two, the decision tree of the hierarchical accounting method includes calculations of the amount of agricultural products transferred outward, calculations of the amount of key construction materials transferred outward, and calculations of the amount of key resources transferred outward.

[0018] As a preferred method, in the calculation of agricultural product transfer volume, for agricultural products, the key materials calculated specifically include staple food and meat. Staple food includes rice, wheat and corn. To simplify the calculation, each type of staple food only considers the urban and rural food demand and feed demand; meat includes pork, beef, mutton and poultry, and meat only considers the residents' consumption demand. The formula is as follows:

[0019]

[0020] In the formula, CE Scope3,i∈agriculturalproduct , C.E. Scope3,i∈meatproduct Scope 3 carbon emissions of staple food ingredients and Scope 3 carbon emissions of meat ingredients; Q demand,i is the demand for the i-th material; Q production,i is the actual production of the i-th material in the city;

[0021] There are three methods for transferring agricultural products:

[0022] 1.1) Investigate the actual output of various grain crops and meat in the target cities, the demand for urban and rural grain, the demand for feed grain and the demand for meat;

[0023] 1.2) The data on the production of various types of grain crops and meat are obtained from the statistical yearbooks of the corresponding cities. The data on the demand for urban and rural grains and meat are calculated based on the data on the per capita food consumption of urban and rural residents; the demand for feed grain is calculated based on the data of the Compilation of Cost and Benefit of Agricultural Products, and the formula is as follows:

[0024]

[0025] Q demand-grain for animals,i∈grain product =P animals,i ×FC per unit animal grain,i ×EF type of grains (6)

[0026] In the formula, Q demand-grain forpeople,i∈grain product , Q demand-meat,i∈meat product are the food demand of the i-th staple food material and the demand of the i-th meat material; P city-level is the number of permanent residents in the city; FC per capita grain,i , FC per capita meat,i are the annual per capita consumption of the ith staple food material or meat material at the city level; Q demand-grain for animals,i∈grain product is the feed grain requirement of the i-th meat material; P animals,i The number of animals raised in that year; FC per unit animal grain,i is the data on grain consumption per unit of livestock product production; EF type of grains It is the apportionment ratio of grain used for feed;

[0027] 1.3) The selected method shall be determined based on the accuracy of the data actually provided by the city.

[0028] As a preferred method, in the calculation of the outward transfer of key construction materials, key construction materials include steel and cement; the demand for construction materials driven by final demand is defined as the urban material demand, and the actual material production in the city is defined as the urban material supply, taking into account the construction demand, transportation infrastructure demand and consumer goods demand;

[0029] For steel materials, the calculation of external transfer volume includes the following four types:

[0030] 2.1) Actual crude steel production data of the target cities, crude steel demand data of construction, crude steel demand data of railway and road transportation infrastructure construction, and actual crude steel content of annual purchases of transportation, machinery, household appliances and other consumer goods;

[0031] 2.2) Carry out calculation;

[0032] The data of urban crude steel production is obtained through statistical yearbooks. The crude steel demand for construction is obtained by calculating the steel consumption of new buildings in the city by building type; the crude steel demand for transportation is obtained by calculating the steel consumption of new railways and highways in the city, and the annual investment in new railway and highway construction in the city or the annual mileage of new railways and highways in the city are obtained for calculation; the unit steel consumption data adopts actual data; the crude steel demand for consumer goods is obtained by calculating the steel content of transportation, machinery, home appliances and other consumer goods purchased in the city annually, and the formula is as follows:

[0033]

[0034]

[0035]

[0036] In the formula, Q demand-steel,building , Q demand-steel,transportation , Q demand-steel,goods are the steel demand for construction, the steel demand for transportation infrastructure, and the steel demand for consumer goods; j is the type of building; A city-level,j is the annual new construction area of ​​the jth building type; SC unit area,i L is the steel consumption per unit new construction area of ​​each building type; railway , L highroad New railway mileage for the year; SC unit length railway,L , S.C. unit length highroad,L I is the steel consumption per unit of new railway mileage; railway , I highroad is the annual investment in new railways; SC unit length railway,I , S.C. unit length highroad,Iis the steel consumption per unit of new railway investment; g is the main consumer product category, including transportation, machinery, home appliances, and other consumer products; P g is the quantity of major consumer goods; SC unit good,g is the amount of steel used per unit product;

[0037] 2.3) Use the method of downgrading data allocation to allocate provincial or national data to cities;

[0038] The crude steel demand for construction is calculated by calculating the steel consumption of new buildings in the province or the country by building type, and then allocated by the proportion of the total area of ​​new buildings in the target city to the total area of ​​new buildings; the crude steel demand for transportation infrastructure is calculated by calculating the steel consumption of new railways and roads in the province or the country, and then allocated by the proportion of transportation infrastructure investment in the target city to the total transportation infrastructure investment; the steel demand for consumer goods is calculated by calculating the steel consumption of consumer goods in the province or the country, and then allocated by the proportion of household consumption expenditure of the corresponding consumer goods category in the target city to the total household consumption expenditure of the corresponding consumer goods category; if all or most of the above data are unavailable, the national annual steel consumption can be obtained and allocated to cities by the number of permanent residents; the formula is as follows:

[0039]

[0040] In the formula, A province(nation)-level,j A is the annual provincial or national new construction area of ​​the j-th building type; city-level A is the annual new construction area of ​​the city; province(nation)-level It is the annual newly built construction area at the provincial or national level; city-level,trans Annual transportation infrastructure investment for the city; province(nation)-level,trans Annual transportation infrastructure investment at the provincial or national level; city-level,g∈G I is the annual household consumption expenditure of the city to which the consumer goods belong; province(nation)-level,g∈G It is the provincial or national annual household consumption expenditure for the consumption category to which the consumer goods belong; Q demand-steel is the annual crude steel demand of the city; SC nation is the total steel demand in the country; P city-level is the permanent population of the target city; P nation-level is the national permanent population;

[0041] 2.4) Determine the selected method based on the accuracy of the data actually provided by the city;

[0042] For cement, the calculation of external transfer volume includes the following four types:

[0043] 3.1) Investigate the actual amount of cement transferred out of the city, or investigate the actual cement production of the city, the annual cement demand of urban construction, the cement demand of urban transportation infrastructure construction, and the cement demand of urban annual industrial infrastructure construction;

[0044] 3.2) Carry out calculation;

[0045] The data of urban cement production is obtained through statistical yearbooks. If there is no data, it is converted to cement products based on the cement clinker production data in the statistical yearbooks. The cement demand for urban construction is obtained by measuring the cement consumption of new buildings in the city by building type. The cement demand for urban transportation infrastructure is obtained by measuring the cement consumption of new railways and highways in the city. The cement demand for urban industrial infrastructure is obtained by measuring the cement consumption converted from the city's industrial fixed asset investment. The formula is as follows:

[0046]

[0047] Q demand-cement,transportation =L railway ×CC unit length railway,L +L highroad ×CC unit length highroad,L (15)

[0048] Q demand-cement,industry =I industry,investment ×CC unit value (16)

[0049] In the formula, Q demand-cement,building , Q demand-cement,transportation , Q demand-cement,goods They are the cement consumption required for construction, the cement consumption required for transportation infrastructure and the cement consumption required for industrial infrastructure; I industry,investment is the original cost of industrial fixed asset investment; CC unit area,i Cement consumption per unit of new construction area for each building type; CC unit length railway,L , S.C. unit length highroad,L Cement consumption per unit of new railway mileage; CC unit value is the unit value of cement material strength;

[0050] 3.3) Use the method of downgrading data allocation to allocate provincial or national data to cities;

[0051] 3.4) Determine the priority of the first three methods based on the actual situation of the city and by comparing the data accuracy.

[0052] As a preferred method, in the calculation of the key resource external transfer amount, the key resource is water resources, and the calculation of the external transfer amount includes the following three types:

[0053] 4.1) Using survey data, obtain the actual water resource production and demand for various types of water resources in the city;

[0054] 4.2) Calculate using statistical data, obtain water supply data through urban water resources bulletins, obtain various urban water demand data through statistical yearbooks, or directly obtain the annual external water transfer ratio and surface water supply of the city;

[0055] 4.3) The selected method shall be determined based on the accuracy of the data actually provided by the city.

[0056] Preferably, in step three, the scope three carbon emission accounting method for each type of material is clarified based on the hierarchical accounting method decision tree in step two; emission factors and calculation parameters adapted to activity data are obtained through accounting tools and databases to estimate or directly obtain the supply chain carbon emission factors of various products in the production, transportation and processing processes, and to classify and calculate the scope three carbon emissions caused by the city's demand for key materials; the scope three carbon emission data for each key material are aggregated to calculate the city-level scope three carbon emissions included in the accounting framework.

[0057] The present invention provides a city-level Scope 3 carbon emissions accounting model based on multi-source data, which adopts the above-mentioned city-level Scope 3 carbon emissions accounting method based on multi-source data.

[0058] The present invention establishes a Scope 3 carbon emission accounting methodology that is suitable for all cities, solves the problem that the current city Scope 3 carbon emission accounting is only applicable to a few cities and the Scope 3 carbon emission accounting reports of different cities cannot be horizontally compared, and provides a basis for enriching the current Chinese city carbon emission accounting data and calculation scope. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 Flow chart of a city-level Scope 3 carbon emissions accounting method based on multi-source data in an embodiment;

[0060] Figure 2 Schematic diagram of the city-level Scope 3 carbon emissions accounting framework in the embodiment. DETAILED DESCRIPTION

[0061] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings and embodiments. It should be understood that the embodiments are only for explaining the present invention and are not intended to limit it.

[0062] Example

[0063] like Figure 1 As shown, this embodiment provides a city-level Scope 3 carbon emissions accounting method based on multi-source data, which includes the following steps:

[0064] Step 1: Build a city-level Scope 3 carbon emissions accounting framework covering a variety of key urban materials (such as Figure 2 shown).

[0065] In the city-level Scope 3 carbon emissions accounting framework, the Scope 3 carbon emissions caused by the demand for each key material are defined as the product of its external transfer amount (if it is a negative value, it is counted as 0) and the supply chain carbon emission factor, as shown in the following formula:

[0066]

[0067] Q import,i =Q demand,i -Q supply,i (2)

[0068] In the formula, CE Scope3 refers to the city-wide carbon emissions; i refers to the type of accounting materials; Q import Refers to the external adjustment amount of the i-th material; EF i is the carbon emission factor of the supply chain of the i-th material; Q demand,i is the demand for the i-th material; Q supply,i is the supply of the i-th material.

[0069] The city-level Scope 3 carbon emissions accounting framework in Step 1 is established based on the following assumptions:

[0070] 1) The outward transfer volume of a city is recorded as the difference between the city's demand and supply (Formula 2);

[0071] 2) Products produced within the city are supplied to the local area first, and the demand gap for key materials caused by final demand behavior is transferred from outside the city to achieve a balance between supply and demand, without considering inventory issues.

[0072] For the supply chain carbon emission factor, this embodiment mainly relies on the China Product Life Cycle Greenhouse Gas Emission Coefficient Library from previous research, and combines the key material supply chain carbon emission factors obtained from the survey. The China Product Life Cycle Greenhouse Gas Emission Coefficient Library provides the national average carbon emission factors for various key materials, with a recommended value of 0.8t CO2 / t for rice, 0.66t CO2 / t for wheat, 340.64kg CO2 / t for corn, 4.84t CO2 / t for pork, 21.71t CO2 / t for beef, 20.82tCO2 / t for mutton, 13.94t CO2 / t for chicken, 2.31tCO2 / t for crude steel, 0.07t CO2 / t for cement, and 0.38kg CO2 / m for agricultural water. 3 、Urban residents’ domestic water use 1.85kg CO2 / m 3 、Industrial water 12.32kg CO2 / m3 .

[0073] Step 2: Establish a decision tree for various key material accounting methods based on data quality grading, and provide judgment basis and required input data format.

[0074] For each type of external transfer activity data, sort them from high to low according to priority, and set a multi-level method; give priority to the actual survey data, use statistical data estimation when the survey data is missing, and then use the downgraded allocation estimation method. In addition, the present invention can provide supplementary methods for accountants, and determine the priority order of supplementary methods based on the accuracy of actual methods.

[0075] The decision tree of the hierarchical accounting method includes the calculation of the amount of agricultural products transferred outward, the calculation of the amount of key construction materials transferred outward, and the calculation of the amount of key resources transferred outward.

[0076] Calculation of agricultural product transfer volume

[0077] For agricultural products, the key materials calculated specifically include staple food and meat. Staple food includes rice, wheat and corn. Each type of staple food only considers the urban and rural food demand and feed demand. According to the data of the National Grain and Strategic Reserves Administration, 38% of grain production is used to meet the food demand of urban and rural residents, and 42% is used to meet the demand for animal feed. The actual grain supply is estimated based on 80% of grain production (Formula 3); Meat includes pork, beef, mutton and poultry. Meat only considers the consumption demand of residents. Considering the wear and tear of meat and the consumption of offal, it is assumed that 90% of meat production is the actual supply (Formula 4), among which the demand for staple food is calculated by converting the original grain. If the data obtained is finished grain data, it needs to be converted. The recommended average conversion factors are 0.825 for grain, 0.7 for rice, 0.67 for beef, 0.73 for pork, 0.6 for poultry and 0.66 for mutton. The formula is as follows:

[0078]

[0079] In the formula, CE Scope3,i∈agriculturalproduct , C.E. Scope3,i∈meatproduct Scope 3 carbon emissions of staple food ingredients and Scope 3 carbon emissions of meat ingredients; Q demand,i is the demand for the i-th material; Q production,i is the actual production of the i-th material in the city.

[0080] There are three methods for transferring agricultural products:

[0081] 1.1) Investigate the actual output of various grain crops and meat in the target cities, the demand for urban and rural grain, the demand for feed grain and the demand for meat.

[0082] 1.2) Data on the production of various types of grain crops and meat are obtained from the statistical yearbooks of the corresponding cities. Data on urban and rural grain demand and meat demand are calculated using data on per capita food consumption of urban and rural residents (Formula 5); data are obtained from the statistical yearbooks of the corresponding cities. If not available, provincial per capita food consumption data are used for calculation, which are obtained from the statistical yearbooks of the corresponding provinces. Feed grain demand is calculated using data from the Compilation of Agricultural Product Costs and Benefits (Formula 6), which is obtained from the National Compilation of Agricultural Product Cost and Benefit Data. The formula is as follows:

[0083]

[0084] Q demand-grain for animals,i∈grain product =P ani mals,i ×FC per unit animal grain,i ×EF type of grains (6)

[0085] In the formula, Q demand-grain for people,i∈grain product , Q demand-meat,i∈meat product are the food demand of the i-th staple food material and the demand of the i-th meat material; P city-level is the number of permanent residents in the city; FC per capita grain,i , FC per capita meat,i are the annual per capita consumption of the ith staple food material or meat material at the city level; Q demand-grain for animals,i∈grain product is the feed grain requirement of the i-th meat material; P animals,i The number of animals raised in that year; FC per unit animal grain,i is the data on grain consumption per unit of livestock product production; EF type of grains It is the allocation ratio of feed grain. It is recommended to be determined based on actual feed survey data by region and animal species. If not available, the basic data of the Agricultural Sector Equilibrium Model (CAPSiM) can be used: rice, 0.099, wheat, 0.063, and corn, 0.73.

[0086] 1.3) The selected method shall be determined based on the accuracy of the data actually provided by the city.

[0087] Calculation of key construction materials transferred out

[0088] Key construction materials include steel and cement. The demand for construction materials driven by final demand is defined as urban material demand, and the actual material production in the city is defined as urban material supply, taking into account construction demand, transportation infrastructure demand and consumer goods demand. Among them, the supply and demand of steel materials are measured in crude steel, and the supply and demand of cement materials are measured in cement.

[0089] For steel materials, the calculation of external transfer volume includes the following four types:

[0090] 2.1) Actual crude steel production data of the target cities, crude steel demand data for construction, crude steel demand data for railway and road transportation infrastructure construction, and actual crude steel content in annual purchases of transportation, machinery, household appliances and other consumer goods.

[0091] 2.2) Carry out calculation;

[0092] The urban crude steel production data is obtained through the statistical yearbook. If it is not available, it is converted to crude steel based on the urban steel production data. The recommended conversion factor is 1.04-1.08kg / kg, that is, 1.04-1.08kg of crude steel is required to produce 1kg of steel.

[0093] The amount of crude steel required for construction is obtained by measuring the steel consumption of new buildings in different building types in the city (Formula 7); it is recommended to use the actual local data for steel consumption per unit area. If there is no local data, the recommended value can be used. For multi-story masonry houses, the recommended value for steel consumption is 30kg / m 2 ; For multi-storey frame houses, the recommended steel consumption is 30kg / m 2 ; For villas and 11-12-story residential buildings, the recommended steel consumption is 51kg / m 2 ; For 11-12-storey residential buildings, the recommended steel consumption is 67kg / m 2 ; For a 30-story high-rise residential building, the recommended steel consumption is 70kg / m 2 ; For industrial plants, the recommended steel consumption is 50kg / m 2 Calculated by building purpose, the recommended steel consumption for new residential, commercial and service buildings is 70kg / m 2 ; Steel consumption for office buildings, scientific research, education, medical buildings, and cultural, sports and entertainment buildings: 51kg / m 2 ; The steel consumption for factories, buildings and warehouses is 50kg / m 2 ; The steel consumption of unlisted buildings is 30kg / m 2 .

[0094] The amount of crude steel required for transportation is obtained by measuring the steel consumption of newly built railways and highways in the city (Formula 8), and the annual investment in new railway and highway construction in the city or the annual mileage of new railways and highways in the city is obtained for calculation; the unit steel consumption data uses actual data, if not, the recommended value can be used, the unit investment steel consumption of new railway construction is 33,300 tons / 100 million yuan, the unit steel consumption of high-speed railway construction is about 3734 tons / km, the unit steel consumption of ordinary railway construction is about 1500 tons / km, and the unit steel consumption of highway construction is about 450 tons / km.

[0095] The crude steel demand for consumer goods is calculated by calculating the steel content of transportation, machinery, household appliances, and other consumer goods purchased in the city (Formula 9), as follows:

[0096]

[0097]

[0098]

[0099] In the formula, Q demand-steel,building , Q demand-steel,transportation , Q demand-steel,goods are the steel demand for construction, the steel demand for transportation infrastructure, and the steel demand for consumer goods; j is the type of building; A city-level,j is the annual new construction area of ​​the jth building type; SC unit area,i L is the steel consumption per unit new construction area of ​​each building type; railway , L highroad The annual new railway (highway) mileage; SC unit length railway,L , S.C. unit length highroad,L The steel consumption per unit of new railway (highway) construction mileage; railway , I highroad The annual investment in new railways (highways); SC unit length railway,I , S.C. unit length highroad,I is the steel consumption per unit of new railway (highway) investment; g is the main consumer goods category, including transportation, machinery, home appliances, and other consumer goods; P g is the quantity of major consumer goods; SC unit good,g The amount of steel used per unit product.

[0100] 2.3) Use the method of downgrading data allocation to allocate provincial or national data to cities;

[0101] The amount of crude steel required for construction is calculated by calculating the steel consumption for new construction in the province or the country by building type, and then allocated according to the proportion of the total area of ​​new construction in the target city to the total area of ​​new construction (Formula 10); Based on the research on cement consumption in the industry, the recommended values ​​for cement consumption for houses of various building purposes are as follows: the recommended concrete consumption for new residential houses, commercial and service houses is 0.42-0.47m 3 / m 2 ; Concrete usage for office buildings, scientific research, education, medical buildings, and cultural, sports and entertainment buildings 0.35m 3 / m 2 ; The amount of steel concrete used in factories, buildings and warehouses is 0.3-0.33m 3 / m 2 ; The amount of concrete used for buildings not listed is 0.3m 3 / m 2The concrete grade and specific mix ratio can be checked by yourself according to the "Ordinary Concrete Mix Ratio Design Code" and other specifications, and the concrete cement density (kg / m 3 ), multiplied by the calculated amount of concrete used, you can get the amount of cement used.

[0102] The demand for crude steel for transportation infrastructure is determined by measuring the steel usage for newly built railways and highways in the province or the country, and then allocating it based on the proportion of the target city's transportation infrastructure investment in the overall transportation infrastructure investment (Formula 11).

[0103] The steel consumption of consumer goods demand is calculated by the province or the country, and then allocated according to the proportion of household consumption expenditure of the corresponding consumer goods category in the target city to the total household consumption expenditure of the corresponding consumer goods category (Formula 12).

[0104] If all or most of the above data are not available, the national annual steel consumption can be obtained and allocated to cities based on the permanent population (Formula 13).

[0105] The formula is as follows:

[0106]

[0107] In the formula, A province(nation)-level,j A is the annual provincial or national new construction area of ​​the j-th building type; city-level A is the annual newly built construction area of ​​the city; province(nation)-level It is the annual newly built construction area at the provincial or national level; city-level,trans Annual transportation infrastructure investment for the city; province(nation)-level,trans Annual transportation infrastructure investment at the provincial or national level; city-level,g∈G I is the annual household consumption expenditure of the city to which the consumer goods belong; province(nation)-level,g∈G It is the provincial or national annual household consumption expenditure for the consumption category to which the consumer goods belong; Q demand-steel is the annual crude steel demand of the city; SC nation is the total steel demand in the country; P city-level is the permanent population of the target city; P nation-level is the national permanent population.

[0108] 2.4) The selected method shall be determined based on the accuracy of the data actually provided by the city.

[0109] For cement, the calculation of external transfer volume includes the following four types:

[0110] 3.1) Investigate the actual amount of cement transferred out of the city, or investigate the actual cement production of the city, the annual cement demand for urban construction, the cement demand for urban transportation infrastructure construction, and the annual cement demand for urban industrial infrastructure construction.

[0111] 3.2) Carry out calculation;

[0112] The data on urban cement production is obtained through statistical yearbooks. If not available, the cement clinker production data in the statistical yearbooks is converted into cement products. This embodiment provides an average conversion coefficient of 0.75 (the cement conversion coefficient of ordinary Portland cement is 0.85, and the cement conversion coefficient of blended cement is 0.65), that is, about 0.85 tons of cement clinker are required to produce 1 ton of cement.

[0113] The amount of cement required for urban construction is obtained by calculating the cement consumption of new buildings by building type in the city (Formula 14), the amount of cement required for urban transportation infrastructure is obtained by calculating the cement consumption of newly built railways and highways in the city (Formula 15), and the amount of cement required for urban industrial infrastructure is obtained by calculating the cement consumption converted from urban industrial fixed asset investment (Formula 16). The formula is as follows:

[0114]

[0115] Q demand-cement,transportation =L railway ×CC unit length railway,L +L highroad ×CC unit length highroad,L (15)

[0116] Q demand-cement,industry =I industry,investment ×CC unit value (16)

[0117] In the formula, Q demand-cement,building , Q demand-cement,transportation , Q demand-cement,goods They are the cement consumption required for construction, the cement consumption required for transportation infrastructure and the cement consumption required for industrial infrastructure; I industry,investment is the original cost of industrial fixed asset investment; CC unit area,i Cement consumption per unit of new construction area for each building type; CC unit length railway,L , S.C. unit length highroad,L Cement consumption per unit of new railway mileage; CC unit value is the unit value of cement material strength.

[0118] 3.3) The provincial or national data are allocated to cities by downgrading data allocation. The specific allocation method and formula are similar to those for steel materials.

[0119] 3.4) The selected method shall be determined based on the accuracy of the data actually provided by the city.

[0120] Calculation of key resource transfer volume

[0121] The key resource is water resources, and the calculation of external transfer volume includes the following three types:

[0122] 4.1) Use survey data to obtain the actual water resource production and demand for various types of water resources in the city.

[0123] 4.2) Calculate using statistical data, obtain water supply data through urban water resources bulletins, obtain various urban water demand data through statistical yearbooks, or directly obtain the annual proportion of water diversion and surface water supply in the city.

[0124] 4.3) The selected method shall be determined based on the accuracy of the data actually provided by the city.

[0125] Step 3: Calculate city-level Scope 3 carbon emissions.

[0126] Based on the hierarchical accounting method decision tree in step 2, the accounting method for scope 3 carbon emissions of various types of materials is clarified; through accounting tools and databases, emission factors and calculation parameters suitable for activity data are obtained to estimate or directly obtain the supply chain carbon emission factors of various products in the production, transportation and processing processes, and classify and calculate the scope 3 carbon emissions caused by the city's demand for key materials; the scope 3 carbon emission data of each key material are aggregated to calculate the city-level scope 3 carbon emissions included in the accounting framework.

[0127] The present invention provides a city-level Scope 3 carbon emissions accounting model based on multi-source data, which adopts the above-mentioned city-level Scope 3 carbon emissions accounting method based on multi-source data.

[0128] This embodiment establishes a Scope 3 carbon emission accounting methodology that is suitable for all cities, solves the problem that the current city Scope 3 carbon emission accounting is only applicable to a few cities and the Scope 3 carbon emission accounting reports of different cities cannot be horizontally compared, and provides a basis for enriching the current Chinese city carbon emission accounting data and calculation scope.

[0129] The present invention and its embodiments are described schematically above, and the description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and designs a structural method and an embodiment similar to the technical solution without creativity without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. A city-level Scope 3 carbon emissions accounting method based on multi-source data, characterized by: The following steps are involved: Step 1: Build a city-level Scope 3 carbon emissions accounting framework covering a variety of key urban materials; Step 2: Establish a decision tree for various key material accounting methods based on data quality classification, and provide judgment basis and required input data format; Step 3: Calculate city-level Scope 3 carbon emissions.

2. The city-level Scope 3 carbon emissions accounting method based on multi-source data according to claim 1, characterized in that: The city-level Scope 3 carbon emissions accounting framework in Step 1 is established based on the following assumptions: 1) The outward transfer volume of a city is recorded as the difference between the city's demand and supply; 2) Products produced within the city are supplied to the local area first, and the demand gap for key materials caused by final demand behavior is transferred from outside the city to achieve a balance between supply and demand, without considering inventory issues.

3. The city-level Scope 3 carbon emissions accounting method based on multi-source data according to claim 2, characterized in that: In the city-level Scope 3 carbon emissions accounting framework, the Scope 3 carbon emissions caused by the demand for each key material are defined as the product of its external transfer amount and the supply chain carbon emission factor, as shown in the following formula: Q import,i =Q demand,i -Q supply,i (2) Where, CE Scope3 refers to the city-wide carbon emissions; i refers to the type of accounting materials; Q import Refers to the external adjustment amount of the i-th material; EF i is the carbon emission factor of the supply chain of the i-th material; Q demand,i is the demand for the i-th material; Q supply,i is the supply of the i-th material.

4. The city-level Scope 3 carbon emissions accounting method based on multi-source data according to claim 3, characterized in that: In step 2, for each type of external transfer activity data, sort them from high to low priority and set up a multi-level method; give priority to using actual survey data, use statistical data to estimate when survey data is missing, and then use the downgraded allocation estimation method.

5. The city-level Scope 3 carbon emissions accounting method based on multi-source data according to claim 4, characterized in that: In step two, the decision tree of the hierarchical accounting method includes the calculation of the amount of agricultural products transferred outward, the calculation of the amount of key construction materials transferred outward, and the calculation of the amount of key resources transferred outward.

6. The city-level Scope 3 carbon emissions accounting method based on multi-source data according to claim 5, characterized in that: In the calculation of agricultural product transfer volume, for agricultural products, the key materials accounted for include staple food and meat. Staple food includes rice, wheat and corn. Each type of staple food only considers the urban and rural food demand and feed demand. Meat includes pork, beef, mutton and poultry. Meat only considers the residents' consumption demand. The formula is as follows: Where, CE Scope3,i∈agriculturalproduct , C.E. Scope3,i∈meatproduct Scope 3 carbon emissions of staple food ingredients and Scope 3 carbon emissions of meat ingredients; Q demand,i is the demand for the i-th material; Q production,i is the actual production of the i-th material in the city; There are three methods for transferring agricultural products: 1.1) Investigate the actual output of various grain crops and meat in the target cities, the demand for urban and rural grain, the demand for feed grain and the demand for meat; 1.2) The production data of various grain crops and various meats are obtained from the statistical yearbooks of the corresponding cities. The demand data of urban and rural grains and meat are calculated through the per capita food consumption data of urban and rural residents; the demand for feed grains is calculated through the compilation data of agricultural product cost and benefit, and the formula is as follows: Q demand-grainforanimals,i∈grainproduct =P animals,i ×FC perunitanimalgrain,i ×EF typeofgrains (6) In the formula, Q demand-grainforpeople,i∈grainproduct , Q demand-meat,i∈meatproduct are the food demand of the i-th staple food material and the demand of the i-th meat material; P city-level is the number of permanent residents in the city; FC percapitagrain,i , FC percapitameat,i are the annual per capita consumption of the ith staple food material or meat material at the city level; Q demand-grainforanimals,i∈grainproduct is the feed grain requirement of the i-th meat material; P animals,i The number of animals raised in that year; FC perunitanimalgrain,i is the data on grain consumption per unit of livestock product production; EF typeofgrains It is the apportionment ratio of grain used for feed; 1.3) The selected method shall be determined based on the accuracy of the data actually provided by the city.

7. The city-level Scope 3 carbon emissions accounting method based on multi-source data according to claim 6, characterized in that: In the calculation of key construction materials outsourcing, key construction materials include steel and cement; the construction materials demand driven by final demand is defined as urban materials demand, taking into account the construction demand, transportation infrastructure demand and consumer goods demand, and the actual material production of the city is defined as urban materials supply; For steel materials, the calculation of external transfer volume includes the following four types: 2.1) Actual crude steel production data of the target cities, crude steel demand data of construction, crude steel demand data of railway and road transportation infrastructure construction, and actual crude steel content of annual purchases of transportation, machinery, household appliances and other consumer goods; 2.2) Carry out calculation; The data of urban crude steel production is obtained through statistical yearbooks. The crude steel demand for construction is obtained by calculating the steel consumption of new buildings in the city by building type; the crude steel demand for transportation is obtained by calculating the steel consumption of new railways and highways in the city, and the annual investment in new railway and highway construction in the city or the annual mileage of new railways and highways in the city are obtained for calculation; the unit steel consumption data adopts actual data; the crude steel demand for consumer goods is obtained by calculating the steel content of transportation, machinery, home appliances and other consumer goods purchased in the city annually, and the formula is as follows: In the formula, Q demand-steel,building , Q demand-steel,transportation , Q demand-steel,goods are the steel demand for construction, the steel demand for transportation infrastructure, and the steel demand for consumer goods; j is the type of building; A city-level,j is the annual new construction area of ​​the jth building type; SC unitarea,i L is the steel consumption per unit new construction area of ​​each building type; railway , L highroad New railway mileage for the year; SC unitlengthrailway,L , S.C. unitlengthhighroad,L I is the steel consumption per unit of new railway mileage; railway , I highroad is the annual investment in new railways; SC unitlengthrailway,I , S.C. unitlengthhighroad,I is the steel consumption per unit of new railway investment; g is the main consumer product category, including transportation, machinery, home appliances, and other consumer products; P g is the quantity of major consumer goods; SC unitgood,g is the amount of steel used per unit product; 2.3) Use the method of downgrading data allocation to allocate provincial or national data to cities; The crude steel demand for construction is calculated by calculating the steel consumption of new buildings in the province or the country by building type, and then allocated by the proportion of the total area of ​​new buildings in the target city to the total area of ​​new buildings; the crude steel demand for transportation infrastructure is calculated by calculating the steel consumption of new railways and roads in the province or the country, and then allocated by the proportion of transportation infrastructure investment in the target city to the total transportation infrastructure investment; the steel demand for consumer goods is calculated by calculating the steel consumption of consumer goods in the province or the country, and then allocated by the proportion of household consumption expenditure of the corresponding consumer goods category in the target city to the total household consumption expenditure of the corresponding consumer goods category; if all or most of the above data are unavailable, the national annual steel consumption can be obtained and allocated to cities by the number of permanent residents; the formula is as follows: In the formula, A province(nation)-level,j A is the annual provincial or national new construction area of ​​the j-th building type; city-level A is the annual new construction area of ​​the city; province(nation)-level It is the annual newly built construction area at the provincial or national level; city-level,trans Annual transportation infrastructure investment for the city; province(nation)-level,trans Annual transportation infrastructure investment at the provincial or national level; city-level,g∈G I is the annual household consumption expenditure of the city to which the consumer goods belong; province(nation)-level,g∈G It is the provincial or national annual household consumption expenditure for the consumption category to which the consumer goods belong; Q demand-steel is the annual crude steel demand of the city; SC nation is the total steel demand in the country; P city-level is the permanent population of the target city; P nation-level is the national permanent population; 2.4) Determine the selected method based on the accuracy of the data actually provided by the city; For cement, the calculation of external transfer volume includes the following four types: 3.1) Investigate the actual amount of cement transferred out of the city, or investigate the actual cement production of the city, the annual cement demand of urban construction, the cement demand of urban transportation infrastructure construction, and the cement demand of urban annual industrial infrastructure construction; 3.2) Carry out calculation; Obtain the city’s cement production data through the statistical yearbook. If there is no such data, convert it to cement products based on the cement clinker production data in the statistical yearbook; The amount of cement required for urban construction is obtained by calculating the cement consumption of new buildings of different building types in the city. The amount of cement required for urban transportation infrastructure is obtained by calculating the cement consumption of newly built railways and highways in the city. The amount of cement required for urban industrial infrastructure is obtained by calculating the cement consumption converted from urban industrial fixed asset investment. The formula is as follows: Q demand-cement,transportation =L railway ×CC unitlengthrailway,L +L highroad ×CC unitlengthhighroad,L (15) Q demand-cement,industry =I industry,investment ×CC unitvalue (16) In the formula, Q demand-cement,building , Q demand-cement,transportation , Q demand-cement,goods They are the cement consumption required for construction, the cement consumption required for transportation infrastructure and the cement consumption required for industrial infrastructure; I industry,investment is the original cost of industrial fixed assets investment; CC unitarea,i Cement consumption per unit of new construction area for each building type; CC unitlengthrailway,L , S.C. unitlengthhighroad,L Cement consumption per unit of new railway mileage; CC unitvalue is the unit value of cement material strength; 3.3) Use the method of downgrading data allocation to allocate provincial or national data to cities; 3.4) The selected method shall be determined based on the accuracy of the data actually provided by the city.

8. The city-level Scope 3 carbon emissions accounting method based on multi-source data according to claim 7, characterized in that: In the calculation of key resource transfer volume, the key resource is water resources, and the calculation of the transfer volume includes the following three types: 4.1) Using survey data, obtain the actual water resource production and demand for various types of water resources in the city; 4.2) Calculate using statistical data, obtain water supply data through urban water resources bulletins, obtain various urban water demand data through statistical yearbooks, or directly obtain the annual external water transfer ratio and surface water supply of the city; 4.3) The selected method shall be determined based on the accuracy of the data actually provided by the city.

9. The city-level Scope 3 carbon emissions accounting method based on multi-source data according to claim 8, characterized in that: In step three, the decision tree of the hierarchical accounting method in step two is used to clarify the accounting method for scope 3 carbon emissions of various types of materials; through accounting tools and databases, emission factors and calculation parameters suitable for activity data are obtained to estimate or directly obtain the supply chain carbon emission factors of various products in the production, transportation and processing processes, and classify and calculate the scope 3 carbon emissions caused by the city's demand for key materials; the scope 3 carbon emission data of each key material are aggregated to calculate the city-level scope 3 carbon emissions included in the accounting framework.

10. A city-level Scope 3 carbon emissions accounting model based on multi-source data, characterized by: It adopts the city-level scope 3 carbon emissions accounting method based on multi-source data as described in any one of claims 1 to 9.

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