2.3.2. Carbon Emission Accounting for Farmers
Based on survey data on farmers’ livelihood capital and primary livelihood activities in the NTLNP from 2016 to 2023, this study refers to the carbon emission inventory method proposed by the IPCC to calculate household carbon emissions. The formula is as follows:
In the formula, represents the household carbon emissions of rural families; represents the production-related carbon emissions of rural households; and represents the consumption-related carbon emissions of rural households.
- (1)
Production Carbon Emissions
The production carbon emissions of rural households are mainly considered in the following three aspects: (1) greenhouse gas emissions caused by agricultural material inputs; (2) greenhouse gas emissions generated by crop planting; and (3) greenhouse gas emissions caused by livestock and poultry farming.
Combining previous research results and consulting relevant experts, it is believed that the carbon emissions generated by agricultural material inputs mainly come from two aspects: First, the direct or indirect carbon emissions caused by the input of agricultural materials such as fertilizers, pesticides, and agricultural films (ground films); second, the carbon emissions caused by the electricity consumption of agricultural plowing and irrigation activities. The carbon emissions generated by agricultural material inputs mainly come from fertilizers, pesticides, agricultural films, agricultural plowing, agricultural irrigation, agricultural diesel, and agricultural machinery. The calculation formula is as follows:
where
is the carbon emissions from agricultural production material inputs;
is the input amount of each agricultural production material; and
is the carbon emission coefficient for each agricultural production material, with values provided in
Table 3.
The main crops in the farmland of the Northeast Tiger and Leopard National Park and its surrounding areas include upland crops such as corn, soybeans, rice (medium-season rice), and potatoes, as well as economic crops such as wood ear mushrooms. Factors affecting carbon emissions include crop planting area, crop type, and their carbon emission coefficients. As the carbon emission coefficient for wood ear mushrooms couldn’t be found in the literature, this paper roughly estimated it based on the main energy-consuming links involved in wood ear mushroom planting. The carbon emission coefficient for wood ear mushroom planting can be considered in three aspects: mushroom spawn making, planting, and drying. Since plastic film and electricity/coal used in drying are calculated in other links, the carbon emission coefficient for wood ear mushrooms mainly comes from spawn making. Spawn is made from raw materials such as sawdust and bran; considering the energy consumption of raw material production, transportation, and processing, the carbon emission for producing 1 kg of spawn is estimated at about 0.5 kg of CO
2 equivalent. Generally, each 1 kg of spawn produces about 0.15 kg of wood ear mushrooms. Thus, the carbon emission coefficient for the spawn link per kilogram of wood ear mushrooms is roughly 3.3 kg of CO
2 equivalent. The carbon emission calculation formula for major crops is as follows:
where
is the carbon emissions from crop cultivation;
is the planting area of each type of crop; and
is the carbon emission coefficient for each crop, with values provided in
Table 4.
In livestock farming, enteric fermentation in animals produces large amounts of CH
4, and manure management also generates significant amounts of CH
4 and N
2O [
17]. Currently, the main types of livestock raised by rural households in the Northeast Tiger and Leopard National Park are cattle, mules, donkeys, sheep, pigs, and chickens. The emission calculation formulas are as follows:
In the formula, the symbols represent the carbon emissions from enteric fermentation and manure management of livestock, respectively;
and
represent the number of each type of livestock; and
and
represent the carbon emission coefficients for enteric fermentation and manure management of each livestock type, with values provided in
Table 5.
- (2)
Consumption Carbon Emissions
Household energy use and structure significantly impact the ecological environment. In this study, carbon emissions from rural household energy use are divided into direct energy-related emissions and consumption-related emissions. Rural households mainly use coal, liquefied gas, gasoline, and electricity, along with large amounts of firewood and straw. Carbon emissions from household energy use depend on the consumption of these energy types and their corresponding emission factors. The calculation formula is as follows:
where
represents the carbon emissions from direct household energy consumption;
represents the usage of each direct energy type (e.g., coal, liquefied gas, gasoline, electricity, firewood, straw); and
represents the carbon emission coefficient from combustion for each energy type, with values provided in
Table 6.
Consumption by farmers is divided into food, tobacco and alcohol, clothing, housing, household goods and services, transport and communications, education, culture and entertainment, medical care, and other services. Therefore, carbon emissions from consumption are determined by the type of household consumption, expenditure, and related emission factors, and the calculation formula is as follows:
where
represents the carbon emissions from living consumption;
represents the expenditure on various types of living consumption; and
represents the carbon emission coefficient for each type of living consumption expenditure, with values provided in
Table 7.
To calculate carbon emissions from household living consumption, the following methods were used: food and beverage purchases were used for food-related emissions, clothing purchases for clothing emissions, housing construction or purchases for housing emissions, durable goods purchases for household goods and services emissions, electricity, communication, and fuel expenses for transport and communication emissions, education and tourism expenses for education, culture, and recreation emissions, and medical expenses for healthcare emissions. Other service expenditures were negligible and excluded from the carbon emission calculations.