Views: 26 Author: Site Editor Publish Time: 2024-11-29 Origin: Site
A carbon sink is a natural or artificial process that removes carbon dioxide from the atmosphere and stores it in reservoirs such as oceans, forests, or soil. This process is essential to mitigating the effects of climate change by reducing the concentration of greenhouse gases in the atmosphere. Carbon sinks can be enhanced in various ways, including reforestation, soil conservation, and protecting existing forests. The concept of carbon sinks is essential to achieving carbon neutrality because it represents a natural way to balance carbon emissions and carbon uptake. Understanding and quantifying carbon sinks is essential to developing effective climate policies and strategies aimed at reducing the overall carbon footprint of human activities.
01 Carbon emissions
Carbon emissions are the process of emitting greenhouse gases (carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride, etc.) to the outside world during human production and business activities. Carbon emissions are currently considered to be one of the main causes of global warming. The largest proportion of my country's carbon emissions (54%) comes from the combustion of fossil fuels in the production process of the power and heating sectors.
Broadly speaking, carbon peak refers to a certain point when carbon dioxide emissions no longer increase to a peak, and then gradually fall back. According to the World Resources Institute, carbon peak is a process, that is, carbon emissions first enter the platform period and can fluctuate within a certain range, and then enter a stable decline stage.
Carbon peak is the prerequisite for carbon neutrality. Early realization can promote the early realization of carbon neutrality. Accordingly, combining the time nodes of Chinas commitments: 1) From now to 2030, Chinas carbon emissions will still be in a climbing period; 2) in the 30 years from 2030 to 2060, carbon emissions will pass the platform period and finally complete the emission reduction task.
Carbon neutrality refers to the total amount of greenhouse gas emissions directly or indirectly generated by enterprises, groups or individuals within a certain period of time, and then offset the carbon dioxide emissions through afforestation, energy conservation and emission reduction, so as to achieve "zero emission" of carbon dioxide.
Carbon sink (Carbon Sink): generally refers to the process, activity and mechanism of removing carbon dioxide from the air. It mainly refers to how much forests absorb and store carbon dioxide, or the ability of forests to absorb and store carbon dioxide.
Research data show that Chinas carbon sink capacity gradually improve, through cultivating and protecting plantation, 2010-2016 China land ecosystem absorb about 1.11 billion tons of carbon, absorb 45% of the same period, visible forestry carbon sink plays an important role in the carbon neutral vision, carbon sink project will help achieve carbon neutral goals in our country.
Carbon capture, utilization and storage, CCUS, is a technology to capture and purify the carbon dioxide emitted in the production process, and then put it in a new production process for recycling or storage. Among them, carbon capture refers to the collection of carbon dioxide from large power plants, steel plants and cement plants and stored in various methods to avoid emissions into the atmosphere.
This technology has the synergistic effect of realizing large-scale greenhouse gas emission reduction and low-carbon utilization of fossil energy, and is one of the important technology choices for the global response to climate change in the future.
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Carbon emission right, namely the origin of certified emission reduction (Certification Emission Reduction, CER). In 2005, with the Kyoto Protocol coming into force, carbon emission rights became an international commodity. The subject matter of carbon emission rights trading is called "certified emission reduction (CER)".
Where do the emission rights come from? Quota primary market and secondary market coexist.
1) The primary market is generally initially issued by the provincial development and reform commission, which is divided into free distribution and paid distribution.
Among them: the paid allocation has a bidding mechanism, following the principle of quota compensation, the same right and the same price, in the way of closed bidding.
2) The secondary market is a market where the controlling enterprises or investment institutions conduct transactions.
Carbon trading is the carbon dioxide emission right as a commodity, and the buyer obtains a certain amount of carbon dioxide emission right by paying a certain amount to the seller, thus forming the trading of carbon dioxide emission right.
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Carbon trading market is a market artificially made by the government through the control of emissions from energy consumption enterprises. Normally, the government determines a total carbon emission and allocates carbon emission quotas to companies according to certain rules. If future corporate emissions are higher than the quota, they need to buy quotas on the market. At the same time, some companies can sell excess quotas through energy conservation and emission reduction technologies and carbon emissions below their quotas, through the carbon trading market. The two sides generally trade through carbon emission exchanges.
If the cost of emission reduction is lower than the market price of carbon trading, the enterprise will choose to reduce emission, and the share generated by emission reduction can be sold to make profits;
When the emission reduction cost is higher than the carbon market price, they will choose to buy from the government, enterprises or other market entities with quotas in the carbon market, so as to meet the emission reduction target set by the government. Those who do not buy enough quotas to cover their actual emissions will face high fines.
Through this set of design, carbon trading market will carbon emissions into part of the enterprise operating costs, and the price of carbon prices guide enterprises to choose the optimal cost of carbon reduction, including energy conservation and emissions reduction, carbon quota purchase, or carbon capture, marketization makes the industrial structure from high energy to low energy transformation at the same time, the whole society cost optimization.
The process of implementing carbon trading can be described in a simple example as follows:
1) At the beginning of the year, there are two companies A and B, Company A emits 100 tons / year annually and B emits 100 tons / year; the carbon quota issued to A is 100 tons / year and the carbon quota issued to B is 100 tons / year; 2) At the end of the year, Company A emits 80 tons and makes profits in the carbon trading market. On the other hand, company B may work overtime to expand production capacity and have no time or funds to do energy saving transformation, resulting in 120 tons of carbon dioxide emissions, which is 20 tons more carbon dioxide compared with the 100 tons of carbon quota given by the government.
At this point, Company B can only buy 20 tons of carbon quota in the carbon trading market.
In this way, the remaining carbon quota of Company A meets the carbon emission needs of Company B, and the carbon trading is finally realized. The final effect is that the total carbon dioxide emissions of A and B are locked at 200 tons, not exceeding the initial quota limit of 200 tons, and meeting the carbon reduction target.
According to the classification of carbon trading, there are two types of basic products in Chinas carbon trading market. One is the carbon emission quota allocated by the government to enterprises, and the other is certified voluntary emission reduction (CCER).
Released in December 2020 "carbon emissions trading management measures (trial)", points out that CCER refers to the renewable energy, forestry carbon sink, methane utilization projects of greenhouse gas emission reduction effect, and in the national greenhouse gas voluntary emission trading registration system of greenhouse gas emission reduction.
First, quota trading, is the government to complete the control target using a policy means, namely in a certain space and time, the control target into carbon emission quotas and assigned to lower governments and enterprises, if the enterprise actual carbon emissions is less than the government allocated quota, the enterprise can trade excess carbon quota, to realize the reasonable allocation of carbon quotas in different enterprises, eventually with relatively low cost.
The second category, as a supplement, introduces voluntary emission reduction market transactions outside of the quota market, namely CCER transactions. The CCER deal accused emissions companies of buying certified amounts of companies that could be used to offset their "carbon offset" emissions.
"Carbon offset" refers to the activities used to reduce greenhouse gas emission sources or increase greenhouse gas absorption sink, and used to compensate or offset other emission sources, that is, the carbon emission of emission control enterprises can be offset by using clean energy to reduce greenhouse gas emissions or increase carbon sink. Offsetting credit is issued after the emission reduction through the implementation of specific emission reduction projects, including renewable energy projects, forest carbon sink projects, etc.
Carbon market in accordance with the proportion of 1:1 give CCER alternative carbon emissions quota, namely 1 CCER equivalent to a quota, can offset 1 tons of carbon dioxide emissions, the carbon emissions trading management measures (trial) " regulation key emissions units can use national certified voluntary emissions offset carbon emissions quota, offset proportion shall not exceed 5% of the carbon emission quota.
The concept of carbon footprint is derived from the "ecological footprint" proposed by the ecological economist William E. Rees in 1992, which is mainly used to measure the impact of human activities on the environment.
Carbon footprint is a kind of "ecological footprint", which reflects the amount of greenhouse gas emissions generated by economic activities (greenhouse gases include carbon dioxide, methane, nitric oxide, chlorfluorocarbons and other gases, usually measured by tons of carbon dioxide).
From the perspective of consumption, the goods or services people buy will drive the upstream circulation, transportation, packaging, production and raw material mining process of carbon emissions —— is equivalent to the "carbon footprint" left by this consumption in the upstream production links.
If the carbon footprint of each production link is very high, economic activity will continue to generate greenhouse gas emissions, exacerbating global climate change. As more and more enterprises put the work of energy conservation and emission reduction and low carbon transformation on the agenda, leading enterprises in the industry began to calculate the carbon footprint from the source of product design to reduce greenhouse gas emissions throughout the whole life cycle of products. For enterprises, carbon footprint can be regarded as a new indicator of environmental protection, which puts forward a higher practical standard for enterprises to understand green economy and practice circular economy. Carbon footprint includes the application of both macro (economy) and micro (unit product) scales:
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To understand the carbon footprint of economic activities, KAYA is mainly used for structure and can be calculated by input-output method.
The classic Kaya carbon emission identity is often used (proposed by Japanese energy economist Yoichi Kaya):
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F= the total amount of carbon dioxide emitted by human beings worldwide
P= Global population
G / P= global GDP per capita
E / G = energy consumption per unit of GDP
F / E= carbon emission intensity per unit of energy supply
The Kaya carbon emission identity uses a simple mathematical formula to link the population size P, economic G (gross national product), and energy consumption E with the total carbon dioxide consumption F produced by human activities.
1.2 Quantity —— input-output method
Input-output is a top-down calculation method, which uses the input-output table, and uses the balance equation to reflect the relationship between production activities and economic subjects. Suitable for macro-level calculations.
To calculate the carbon footprint of a product or service, the life cycle assessment method is mainly used. Life Cycle Assessment: Many countries in the world have established carbon footprint standards and specifications. In October 2008, the British Standards Association formulated and issued the carbon footprint accounting standards for goods and services- - - - "public accessible specifications". The carbon footprint of goods and services is roughly divided into two categories: one is the carbon emissions from the manufacturer to the consumer (Business to customer, B2C), which covers the carbon emissions generated throughout the life cycle of the product; the carbon emissions from the manufacturer to the manufacturer (Business to business, B2B), which only considers the greenhouse gas emissions released before the product reaches the new business organization.
B2C: The evaluation covers the assessment of greenhouse gas emissions throughout the life cycle from raw materials, process manufacturing, distribution and retail, consumer use to processing or recycling.
B2B: This evaluation includes the evaluation of greenhouse gas emissions from raw materials from production to completion, including the whole process of distribution sales and road transportation.
The carbon footprint accounting of the products can be roughly divided into four aspects: first, the carbon emissions directly generated by the activities of enterprises or departments; second, the carbon emissions generated by the use of energy resources during the whole production process; third, the carbon emissions generated by the total supply chain of goods and services; and the carbon emissions in the whole life cycle including transportation and use.
In conclusion, the definition of carbon footprint is summarized as follows: Carbon footprint is an accounting of the total greenhouse gas emissions directly or indirectly caused by a product or activity as a unit of carbon dioxide quality equivalent. The greenhouse gases are the greenhouse gases listed in the Kyoto Protocol and its successors.
The life cycle evaluation method (Life cycle assessment, LCA), as an evaluation tool, is mainly used to evaluate and calculate the whole life cycle process of products or services, that is, the energy consumption and environmental impact from cradle to grave. Cradle to grave generally refers to the collection of raw materials from the product to the production, processing, transportation, consumption and use, and final waste disposal (ISO, 1998). At present, the more commonly used life cycle evaluation methods can be divided into the following three categories (according to the system boundary setting and model principle of the method):
(1) Process life cycle evaluation (Process-based, PLCA), which is the most traditional life cycle evaluation method, and is still the most mainstream evaluation method (ISO, 199 SETAC, 1993,1998).
According to the ISO Principles and Framework of Life Cycle Evaluation (ISO14040) (ISO, 1998), this method mainly includes four basic steps: target definition and scope definition, list analysis, impact assessment and interpretation of results, and each basic step includes a series of specific steps. Process life cycle evaluation method, using the "bottom-up" (bottom-up) model, based on the inventory analysis, through the field monitoring research or actually his database data (secondary data) collection to obtain products or services in the life cycle of all the input and output data, to calculate the research object of the total carbon emissions and environmental impact. For the micro-level (specific product or service aspects) of the carbon footprint calculation, the process life cycle method is generally used. The advantage of this method is that it can accurately assess the carbon footprint and environmental impact of a product or service, and the accuracy of its evaluation objectives and scope can be set according to specific objectives. However, due to the strong subjectivity of its boundary setting and the cut-off error, the evaluation results may not be accurate enough, and even have contradictory conclusions.
(2) Input-output life cycle evaluation (Input-outputLCA, I-OLCA): overcomes the disadvantages of boundary setting and list analysis in the process life cycle evaluation method, and introduces the economic input-output table, also known as the economic input-output life cycle evaluation (Economicinput-outputLCA, EIO-LCA).
This method is mainly using "top-down" (up-bottom) model, when evaluating the environmental impact of specific products or services, first "from" said the accounting industry and sector level energy consumption and carbon emissions level, this step needs to use the interval published (not years published) input output table, and then according to the balance equation to estimate and reflect the relationship between the economic subject and the evaluated object, according to the corresponding relationship and the overall industry or sector energy consumption for specific products. This method is generally applicable to the calculation at the macro level (such as countries, departments, enterprises, etc.), and is less applied to the evaluation of single industrial products. The advantage of this method is that it can fully calculate the carbon footprint and environmental impact of products or services. However, the evaluation of this method is restricted by the input-output table. On the one hand, the timeliness is not strong, because the table is released regularly for several years. On the other hand, the departments in the table may not be able to correspond with the evaluation object, so it is generally impossibleEvaluation of a specific product, at the same time can not fully calculate the entire product life cycle emissions (operation and use and waste gas treatment stage are not calculated.
(3) mixed life cycle evaluation (Hybrid-LCA, HLCA), refers to the process analysis and input-output method of life cycle evaluation method, according to the combination way, now can be divided by its mixed way into three life cycle evaluation model: (A) layered mixing, (B) based on input-output mix and (C) integrated mix. In general, the advantage of this method is that it can not only avoid the truncation errors, but also compare the targeted evaluation of the specific product and its whole life cycle stages (use and waste stages). However, the first two models are prone to double calculation and not conducive to the system analysis function of input-output table; the last model remains in the hypothesis stage.
Product carbon footprint evaluation mainly includes goods and services. The existing product carbon footprint assessment standards are mainly the UK PAS2050:2008 Code for Greenhouse Gas Emissions for Goods and Services (PAS2050) and the Japanese carbon footprint label certification standard TS Q 0010. Most of the existing literature uses PAS 2050 and its guidance documents to evaluate the product carbon footprint. The evaluation standard of product carbon footprint is basically based on the life cycle method to evaluate the carbon footprint of the whole product life cycle. It not only includes a certain stage of product production, but also takes into account the raw material mining and manufacturing of products, and waste disposal stages. To achieve this goal, we should adopt the life cycle evaluation method to improve the reliability and convenience of carbon footprint accounting.
The general steps of product carbon footprint assessment are taken in the following five steps:
1. Establish a product life cycle flowchart. The flow chart shall include the entire life cycle of the product, including materials, energy and waste, and then establish different flow charts according to the different stages of the product life cycle. Before establishing the flow chart, the selected product object is B2C or B2B.
2. Determine the product boundaries. Product boundaries are determined according to the relevant provisions of the ISO 14025 series standards, which is consistent with the defined system boundaries; if the specified product category boundaries are not applicable to evaluating the selected product, the system boundaries are redefined according to the standard principles.
3. Collect the data known as carbon emission factors. Collect production activity data and carbon emission factors throughout the entire phase of the life cycle of the product.
4. Calculate the product carbon footprint. Use the carbon footprint calculation formula, pay attention to quality conservation, ensure that no item is omitted, and ensure that all input, output and waste are included in the calculation formula.
5. Test for the uncertainty. This work is not necessary and can be determined whether or not, but the test uncertainty is conducive to improving the accuracy of the calculation results and having a better understanding of the quality of the collected data.
Enterprise carbon footprint assessment, also known as carbon inventory, is an accounting process of carbon footprint quantification in a certain space and time range. The result of a carbon inventory can be a carbon inventory that considers only the sources and amounts of greenhouse gas emissions, or a complete carbon inventory report that disclosed carbon emissions. More use of carbon inventory standards include a series of standards for the Greenhouse Gas Protocol (GHGProtocol), which consists of two guidelines: the Greenhouse Gas Protocol for Corporate Accounting and Reporting, the Quantitative Criteria for the Greenhouse Gas Protocol Project) and the ISO 14064 standards. At present, it has been adopted by many international energy conservation and emission reduction activity organizations and more than 900 enterprises such as Shell, IKEA, Ford and SONY.
The general steps of the enterprise carbon footprint assessment are taken in the following four steps:
The first step is to determine the organizational boundary of the reporting enterprise. —— From the perspective of the enterprise, determine the production facilities, office facilities and office space owned by the enterprise. This accounting process should include its subsidiaries, transfer investment companies, joint ventures and other independent legal persons or unincorporated institutions.
The second step is to identify direct and indirect sources of energy consumption. The —— protocol (GHG Protocol) divides greenhouse gas emissions into three areas according to their sources, with similar ISO 14064 standards.
The specific division of the three ranges is as follows: 1. Direct emissions of greenhouse gases. The emission sources held or controlled by the company (vehicles and other equipment) and the emission sources of the process equipment are the direct emission channels of greenhouse gases.2. The electric emissions of greenhouse gases. Emission sources generated by company power consumption and working at power production facilities. It mainly includes direct procurement or other means into the companys applicable scope of power energy.3. Other indirect emissions of greenhouse gases. Indirect emissions of greenhouse gases are the result of activities other than emission sources held or controlled by the company, mainly including raw materials for production, transportation of purchased fuel, and sales of products and services.
The third step is to quantify both direct and indirect energy consumption. Collect data and select carbon emission factors Use computing tools to apply the data to the enterprise level. Carbon footprint accounting considers the total amount of carbon dioxide emissions in a specific period of time, and other greenhouse gases need to be converted into carbon dioxide equivalent before calculating the carbon footprint accounting. The CO 2 equivalent is obtained by multiplying the amount of greenhouse gases by their global warming potential. The Intergovernmental Panel on Climate Change (IPCC) has already disclosed its global warming potential for a 100-year cycle. Methods to detect density and flow rates to directly measure greenhouse gas emissions are not common. It is a more common practice to calculate carbon emissions according to the chemical equivalent or material balance of a particular facility or process. However, the most common way to calculate greenhouse gas emissions is to use published carbon emission factors. The carbon emission factor is calculated and mainly indicates the relationship between the total amount of the emission source and the amount of activity, usually the ratio. In order to calculate more accurate emissions with activity data and carbon emission factors, it is necessary to use the basic formula of carbon footprint calculation: the materials used in a specific period of some activity, energy and the waste * carbon emission factor generated during this period.
Step four is to select a base year. Select the base year and compare the emissions of the relevant years, and if the internal structure of the enterprise changes, the data of the base year must be recalculated.
The existing carbon footprint research scale mainly include macro research and micro research. From the macro scale, the main consideration is the impact of international trade and industrial structure. The future research needs to be further improved. Considering the consumption mode, income level and other hidden influencing factors, we can strengthen the research on the relationship between ecological and environmental security and carbon footprint. From the perspective of micro-scale, most of the existing micro-scale studies do not take into account the time and space of carbon footprint, and only for a specific organization, not from the whole, and lack of substantive research practice.
In practice, there are significant differences in the measurement content, methods and technical route of carbon footprint measurement at different research scales. Fully considering the carbon footprint accounting different research scale differences, in order to more comprehensive accounting carbon footprint, this paper from the product scale, personal scale, family scale, enterprise (organization) scale, urban and regional scale, national, regional and economic scale, specific industry / sector seven different scale respectively analyzed the carbon footprint accounting.
One of the most involved aspects of carbon footprint research is product research, and its measurement method generally adopts the life cycle evaluation method. The product carbon footprint is used to calculate the total greenhouse gas emissions of a product throughout its life cycle, which generally includes raw materials and their acquisition, production, sales, use, and disposal. The first application of life cycle method in carbon footprint accounting is the carbon footprint study of carbon saving fund in products. Enterprises can calculate the carbon footprint of their products as the "carbon label" on the products to sell to consumers, so as to guide consumers to buy. In July 2007, a potato chip production company of PepsiCo first used the carbon footprint accounting method to analyze its products. It was the companys products as the "first person to eat crab" and the first to be labeled with a "carbon label". In addition, the British Standards Institute has also published the Standards for the Assessment of goods and Services (PAS 2050). This approach is based on relevant research on the product carbon footprint by the Carbon Trust (Carbon Trust), complementing existing UK criteria for carbon footprint assessment. PAS 2050 The purpose is to help enterprises to calculate and analyze the greenhouse formed by their own activitiesThe total gas displacement, and provide enterprises in each link can be applied emission reduction measures
The process of estimating carbon emissions in their daily lives is a personal carbon footprint, generally including clothing, food, housing and transportation. In 2007, the Department of Environmental Food and Rural Affairs became the first department to provide a personal-scale carbon footprint accounting tool for the public. Later, the University of Berkeley and the China Green Carbon Sink Foundation also launched carbon calculators for individuals to calculate the carbon footprint generated by their food, clothing, housing and transportation. People can calculate the total amount of carbon dioxide emitted by their daily activities on the Internet at any time. The carbon calculator calculates total carbon dioxide emissions based on energy-consuming equipment, household appliances and vehicles used by individuals or households, and makes recommendations on energy conservation and consumption reduction. The California Environmental Protection Agency also asked the University of Berkeley to develop and design a carbon footprint calculator, which uses the life cycle method for accounting, and is now a relatively complete and comprehensive carbon footprint calculator. Since 2006, some Chinese websites have also published some carbon dioxide emission calculators for the public. The carbon footprint calculators described above are bottom-up and calculated based on the daily life activities. There is also a top-down calculation method, that is, based on the income and expenditure of each household, combined with the analysisEnvironment, calculating the average amount of carbon dioxide emissions by household or income class in a country
Household carbon footprint accounting is a relatively mature content in foreign carbon footprint research, which started earlier. The combination of the life cycle evaluation method and the inter-regional input-output analysis model, supplemented by the survey of consumer expenditure, and the impact of national trade on the US household carbon footprint is analyzed.
In the existing organizational carbon footprint analysis research, for enterprises and schools, enterprises are the possible bearers of carbon emission costs, so enterprises pay great attention to carbon footprint accounting, which is conducive to enterprises to better understand the impact of their production and operation on climate, and is conducive to formulating more effective energy saving and emission reduction plans. Enterprise carbon footprint has a problem of double calculation, if an enterprise calculate carbon footprint is considering the enterprise all possible carbon footprint on the supply chain, then other companies in the supply chain, can lead to double calculation, enterprises should consider only in certain specific production supply chain for the carbon produced by the product production footprint. Therefore, in order to avoid double calculation, the enterprise carbon footprint assessment should build a method for the upstream and downstream enterprises in the supply chain to share the carbon emission responsibility in the supply chain. Enterprises often choose life cycle evaluation methods in their carbon footprint accounting. For example, Fonterra commissioned three research institutions to analyze and evaluate the carbon footprint of their corporate activities respectively, and the three research institutions all adopted the life cycle evaluation method in their accounting. The Stockholm EnvironmentalResearch Institute (Stockholm EnvironmentalResearch Institute) calculated the carbon footprint of the daily work activities of UK schools in 2001, using a combination of process analysis and input-output analysis.studyThe total carbon dioxide emissions from the daily activities of British schools were 92 0,000 tons, accounting for 1.3% of the total active carbon dioxide emissions in the UK, which was relatively higher. The direct emissions are mainly caused by the heating equipment, But the campaign represents only 26% of each schools total carbon emissions, The remaining 74% were all indirectly caused, The classroom uses the largest proportion of electricity consumption, It reached 22%, Next up are other industrial product uses and school shuttle buses, That accounted for 14 percent, In addition, other activities with a relatively small proportion, Including other traffic, Accounting for 6%; Teaching style equipment and chemical tests used in class, Each accounted for 5%; , Paper consumption, Accounting for 4%; The other two activities with the smallest share are only 2% each, They are product and services and mining and quarrying activities. The study of the British school carbon footprint through the questionnaire form to obtain the first more detailed data, and on the basis of the process analysis, into the input and output analysis, which makes the method obtained the characteristics of the top-down, and obtained the bottom-up advantage, the final calculation results are accurate and comprehensive, error is relatively small. In conclusion, this mixed analysis pattern perfectly integrates a combination of two analysis methods, wholeThe advantages of the two methods complement each other and improve the shortcomings of the use of individual methods, which also opens up a new thinking side for the future carbon footprint accounting research.
In recent years, more attention has been paid to urban and regional carbon footprint accounting, and more diverse research methods. We can calculate the carbon footprint of urban areas by the principle of enterprise accounting carbon footprint, because in some cases, the urban area can be regarded as a relatively large enterprise. However, there is still a big difference between cities and enterprises, namely, the boundary of carbon sink and carbon bank contained in urban areas. In addition, in addition to providing services to local residents, a city or region will also provide services to residents outside the scope, which is one of the reasons why urban greenhouse gas emissions are significantly higher than the national average greenhouse gas emissions.
From the perspective of globalization and open economy, the current international climate negotiations are based on countries, regions or economies, so the national carbon footprint accounting of countries has become one of the areas that countries attach great importance to. We can divide the national carbon footprint into two types: national and homeland, while the relatively rich national activities generally produce more carbon footprint than they should contain. In addition to the carbon footprint generated by their land area, there is also the carbon footprint produced by some relatively poor countries.
With the growth rate of carbon emissions in the transportation industry increasing year by year, it is urgent to study the carbon footprint of the transportation industry. At present, the existing carbon footprint studies on the transportation industry at home and abroad only focus on some aspects such as road infrastructure, vehicle production, fuel consumption, or comprehensive and unified analysis of the possible pressure caused by a certain traffic activity on the environment, and lack the analysis and evaluation of the transportation industry as a whole.
British scholar Gilliam (2008) took the laparoscopic surgery of a hospital for 10 years as an example to calculate the carbon footprint and study the carbon dioxide emissions of the surgical cylinder. The data shows that surgery is increasing and cylinder use is getting shorter, but greenhouse gas emissions are not reduced. At the same time, British scientists Cole (2009) investigated the national health insurance system carbon footprint, and the classification of the research, the national health insurance system emissions of carbon dioxide is a quarter of the public sector emissions, to effectively reduce the British national health insurance system carbon footprint provides measures such as health care at home.
Compared with the carbon footprint of energy research by different scholars in the world, its ultimate goal is to maximize energy conservation and emission reduction.11 Specifically speaking, British scholar Post (2006) has done research in the power industry, Mainly compared the carbon footprint of different energy sources used for power generation, Studies have shown that fossil fuels (such as coal, oil and natural gas) have the largest carbon emissions during electricity production, Leaving behind the most carbon footprint; Energy saving resources such as wind, tidal, water, solar, etc. have relatively low carbon content, It has very little carbon emissions from its electricity production process, The carbon footprint all comes from the transportation phase before production; There has been no absolute pollution-free, emission-free energy sources, But energy-saving resources are already the best resources, The carbon footprint has been significantly reduced, Emissions of greenhouse gases are somewhat controlled. Giurco and Petrie (2007) studied the carbon footprint of other substances (such as copper and cement), and used a dynamic substance flow model to calculate the carbon footprint of other substances and compare the effects of greenhouse gases in different situations. After the future estimation, the result is concluded that the copper production process has greatly improved the emission of greenhouse gases, but the waste of non-renewable resources is serious, and various channels can be adopted, such as the recycling of copper waste for technical production, Strengthen the cooperation between departments to save metal capital from the source of production
In summary, it is essential for companies to fully understand carbon emissions, peaking, neutralization, carbon sinks, rights, trading, quotas and footprints, and to manage them strategically, in order to play their role in the global efforts to combat climate change. By adopting effective strategies and utilizing mechanisms such as carbon trading and emission rights, companies can contribute to a sustainable future and help achieve carbon neutrality goals.
