Carbon neutrality should beCarbon emissions（carbon source) andcarbon fixation（carbon sink) to understand these two sides. Carbon emissions can be generated by both human and natural processes. The anthropogenic process mainly comes from two large blocks, one is the combustion of fossil fuels to form carbon dioxide (CO₂) to the atmosphere, and the second is land use change (the most typical is that the carbon in the soil is oxidized into carbon dioxide and released into the atmosphere after deforestation); There are also many processes in nature that can release carbon dioxide into the atmosphere, such as volcanic eruptions and underground spontaneous combustion of coal. However, it should be noted that:For more than a century, natural carbon emissions have been more than man-made carbon emissions, and the impact on changes in atmospheric carbon dioxide concentration is almost negligible..

Carbon fixation also has two major categories of natural fixation and man-made fixation, and is dominated by natural fixation.. The most important natural carbon sequestration processes come from terrestrial ecosystems. Among the many types of terrestrial ecosystems, forest ecosystems account for the majority. The so-called man-made fixation of carbon dioxide, one way is to collect carbon dioxide and convert it into other chemicals through biological or chemical processes, and the other way is to store carbon dioxide deep underground and deep in the ocean.

In the past few decades, about 54% of the carbon dioxide emitted by human beings has been absorbed and fixed by natural processes, and the remaining 46% is retained in the atmosphere. Of the 54% of natural absorption, 23% is done by the ocean and 31% by terrestrial ecosystems. In recent years, for example, the world's annual carbon emissions have been about 40 billion tons of carbon dioxide, of which 86% comes from fossil fuel combustion and 14% from land-use change. 18.4 billion tons (46%) of these 40 billion tons of carbon dioxide are added to the atmosphere, resulting in an increase in atmospheric carbon dioxide concentration of approximately 2ppmv.

so-calledCarbon neutrality is to make the atmospheric carbon dioxide concentration no longer increase. We can imagine this: our economic and social operation system, even if it is capable of achieving carbon neutrality, there will definitely be a part of the "carbon dioxide that has to be emitted", and on the one hand, there will be about 54% of the natural carbon sequestration process., The rest must be eliminated through ecosystem carbon sequestration, artificially converting carbon dioxide into chemical products or storing underground. Only after the amount of emissions is equal to a fixed amount is carbon neutrality achieved. from this,Zero emissions of carbon and the same carbon are two different concepts, which are marked by the fact that the concentration of carbon dioxide in the atmosphere is no longer increasing..

China's current annual carbon dioxide emissions are about 10 billion tons, which is about 1/4 of the global total emissions.. Such a large amount of emissions is mainly determined by China's total energy consumption and energy consumption structure. my country's current total energy consumption is about 5 billion tons of standard coal, of which coal, oil and natural gas together account for nearly 85%, and other non-carbon energy sources account for only a little more than 15%. Among the three types of fossil energy, coal, oil and gas, the coal with the highest carbon emission factor accounts for nearly 70%.In my country's energy consumption structure, coal accounts for such a high proportion, which is unique among major countries in the world..

Of the total annual emissions of about 10 billion tons of carbon dioxide, power generation and heating account for about 4.5 billion tons, the operation of buildings after completion (mainly coal and gas) accounts for about 0.5 billion tons, traffic emissions account for about 1 billion tons, and industrial emissions account for about 3.9 billion tons.The four major areas of industrial emissions are building materials, steel, chemicals and non-ferrous metals., and the bulk of building materials emissions is cement production (cement to limestone (CaCO₃) As raw material, after calcination into calcium oxide (CaO), it is bound to form carbon dioxide emissions).

The carbon dioxide emissions from the electricity/heat production process should be "accounted" for in the electricity consumption sector. According to further research, it was found that of the 4.5 billion tons of carbon dioxide, about 2.9 billion tons should eventually be recorded as industrial emissions, and about 1.26 billion tons should be recorded as operating emissions after the building is completed. Therefore, we say that China's industrial emissions account for about 68% of the total emissions, and such a high proportion is unique among all major countries. this is determined by factors such as China's "factory of the world", rapid urbanization and compressed economic and social development.

According to the current situation of carbon dioxide emissions in China, it is very easy for us to infer that China's carbon neutrality needs to build a "three-end joint power system".The first end is the power endThat is, the coal-based power/heat supply side should be transformed into wind, light, water, nuclear, geothermal and other renewable energy and non-carbon energy.The second end is energy consumption.That is, green electricity and green hydrogen are used to replace coal, oil and gas in the production process of building materials, iron and steel, chemical industry, nonferrous metals and other raw materials. In the cement production process, the use of limestone as raw materials is reduced to a minimum, and coal, oil and gas are replaced by green electricity, green hydrogen and geothermal energy in transportation and construction. An important prerequisite for the energy consumption side to achieve such a replacement is that the national green power supply capacity is almost in a state of "responding to requests.The third end is the carbon fixation endIt is conceivable that no matter how the front two ends develop, it is technically impossible to achieve zero carbon emissions. For example, the carbon dioxide generated by the "carbon reduction" in the production process of coal, oil, and gas, or the cement production process The part of carbon dioxide that will always be produced in China, as well as the power production itself, can only hope for the distant future to truly achieve "zero-carbon power. Therefore, we have to fix the "carbon dioxide that has to be emitted" with various man-made measures, the most important of which is ecological construction, in addition to industrial utilization after carbon capture, and storage in the strata and deep sea.

Traditionally, the power supply system includes three parts: power generation, energy storage and transmission. From the perspective of the "new power supply system" that the industry often talks about, users should also be considered as a whole.From the perspective of achieving carbon neutrality, China's future power supply system should have the following six characteristics.

First, the installed power capacity should be doubled.. At present, China's installed power generation capacity is about 2.4 billion kilowatts. If the following factors are considered:(1) green electricity substitution and green hydrogen substitution for fossil energy will be realized in the future;(2) From the history of most of the first-developing countries in the world, the per capita GDP will increase significantly from US $10,000 to US $30 thousands or 40 thousands, and the per capita energy consumption will increase significantly;(3) The "output capacity" of fluctuating energy sources such as wind and light is only about 1/3 that of traditional thermal power, so China's installed capacity by 2060 needs to be at least 6 billion to 8 billion kilowatts.

Second, wind and light resources will gradually become the main power generation and energy supply resources.. Among them, the western wind, light resources and coastal continental shelf wind resources are the main body, and the scattered (especially rural) light and heat resources are the supplement.

Third, the "stable power supply" will gradually transform from the current thermal power to nuclear power, hydropower and comprehensive complementary non-carbon energy..

Fourth, it is necessary to use energy storage, conversion, regulation and other technologies to make up for the natural defects of large fluctuations in wind and light resources..

Fifth, thermal power still needs to be available, but it is mainly used as emergency power supply and part of regulating power supply.. At the same time, thermal power should complete clean and low-carbon transformation. If conditions permit, natural gas should be used instead of coal to reduce the intensity of carbon dioxide emissions.

Sixth, on the existing basis, multiply the transmission infrastructure to transmit abundant power from the west to the central and eastern consumption areas. At the same time, strengthen the construction of power distribution infrastructure and enhance the ability to absorb distributed energy.

In such power supply systems, the goal of carbon neutrality itself requiresAbout 70% of future electricity will come from wind and light power generation.The other 30% of stable power supply, regulating power supply and emergency power supply should also reduce the total installed capacity of thermal power as much as possible.Because of this, the future needs to promote "revolutionary" progress in power generation technology, energy storage technology and transmission technology..

Power generation technology should provide support for green and low-carbon power production. It is necessary to focus on promoting the progress of renewable energy power generation technology, especially the development of the following technologies:(1) Although photovoltaic power generation technology has developed to the extent that it can be connected to the Internet at a low price, this type of technology still has the potential to reduce costs and increase efficiency. (2) Solar thermal power generation technology is grid-friendly, which can ensure stable output and can also be used for peak shaving, but the current power generation cost is too high, in the future, breakthroughs should be sought in materials and devices;(3) Wind power generation technology is basically equipped with the conditions for affordable access to the Internet. In the future, efforts should be made in the manufacture of high-power wind turbines, the utilization of higher space wind power, and the construction of farther offshore wind power stations;(4) Geothermal energy is widely distributed and large in total, but the energy density is too low;(5) Biomass energy is also renewable energy. At present, biomass power generation technology is mature, but its proportion in the total power supply is limited;(6) the total amount of ocean energy and tidal energy is not small, but its utilization technology needs to be improved;(7) the degree of traditional hydropower development in China has been relatively high, and there is still great potential for the development of the upper reaches of the Yarlung Zangbo River and Jinsha River in the future.

In addition to the above renewable energy generation, the public has to accept this reality:To achieve carbon neutrality, nuclear power has to be developed to a greater extent, because nuclear power should be an important part of a "stable power supply".. In addition, thermal power has to play a role in "stabilizing power supply", "emergency power supply" and "regulating power supply". Because of this, "carbon-free power" is difficult to achieve for a long time, unless we collect the carbon dioxide emitted by thermal power stations. Get up and then seal up or use it.

Energy storage technology will occupy a prominent position in the future power supply systemThis is because wind and photovoltaic power generation have natural volatility, and the user side also has volatility, which requires energy storage technology to make adjustments. It can be said that without environmentally friendly, reliable and relatively inexpensive energy storage technologies, the goal of carbon neutrality will be defeated. Energy storage is the most important power flexibility adjustment method, including physical energy storage, chemical energy storage and electromagnetic energy storage three categories, and flexibility adjustment and thermal power unit flexibility transformation, vehicle network interaction, electric fuel, electric heat and other methods and technologies.

There are four main types of physical energy storage. The first is pumped storage power station, which is the most mature technology. Relying on the eastern mountainous areas, the total number of pumped storage power stations under construction and planning is very large, but how to build pumped storage power stations in the western region, which is rich in renewable energy, still needs to be explored. The second is compressed air energy storage, which mainly uses underground salt caverns, mines and other spaces. This type of technology is still in its infancy in my country. The third is gravity energy storage. Simply put, it uses cliffs, slopes and other terrain to lift heavy objects when there is more power, and when electricity is needed, put down heavy objects and use potential energy to do work. This kind of technology is still in the experimental stage in our country. Fourth, flywheel energy storage, which is a mature technology, but its energy density is not high.

Chemical energy storage is the use of various types of batteries, well-known lithium batteries, sodium batteries, lead-acid (carbon) batteries, flow batteries, liquid metal batteries, metal-air batteries, fuel cells (hydrogen, methane) and so on. Different batteries have different application scenarios, and they have an indispensable position in the future power supply system, but they will encounter problems such as battery recycling, environmental protection, and resource supply in the future.

Electromagnetic energy storage is mainly supercapacitor and superconducting material energy storage, at present, its role remains to be seen.

The flexible transformation of the existing thermal power unit refers to making its "work-out capacity" flexible. The unit can exert 100 per cent of its power generation capacity at peak power consumption and only "work-out" 20 or 30 per cent at low power consumption. Once this technology is mature, it should be very useful, especially in the early and middle stages of achieving the "double carbon" goal, it should be used as the main technology. Vehicle-network interaction refers to the interaction between electric vehicles and the power grid. Simply put, a large number of electric vehicles will be integrated into a very large energy storage system in the future. If some of them are charged centrally when there is more power in the grid, and when the power is insufficient, some of them will transmit power to the grid. To smooth the role of peaks and valleys. This idea is beautiful and a bit "romantic", but how to transform theoretical possibilities into practical feasibility, it is estimated that business models will have to be innovated.

Power-to-fuel is the conversion of excess electricity into fuels such as hydrogen and methane, which are then used to generate electricity when there is a shortage of electricity. Electric heat energy storage is water, oil, ceramics, molten salt and other heat storage materials to convert excess electricity into heat storage, when needed for the user to release heat.

The third major component of the new power supply system is the transmission network.. From the logical analysis of achieving carbon neutrality, China's future power grid will have the following outstanding features:(1) the scale of long-distance transmission will increase several times on the existing basis, which means that the demand for transmission infrastructure construction is huge to transmit clean power from the west to the eastern consumption area;(2) in order to coordinate and guide the power generation resources and user demand on a large spatial scale, the large power grid should be the basic form;(3) The construction of distributed microgrids close to end users (such as industrial parks, small towns, etc.) will be valued and will become an effective supplement to the large power grid;(4) In order to solve the high proportion of renewable energy with strong volatility and the high proportion of power electronic devices, it is necessary to achieve a qualitative leap in the intelligent control technology of the power grid.

From the above introduction, we can see that the establishment of a new power system is actually a process of gradually "squeezing out" thermal power, or strictly speaking, it is a process of minimizing the proportion of thermal power installed, and the remaining thermal power must also be "Clean" transformation. China has sufficient wind and solar energy, and in theory, the resources are absolutely sufficient. But can we make use of these widely distributed, low energy density wind and light resources, and ensure that the electricity price is relatively cheap, and develop advanced technology, especially energy storage technology is the key!

There are two key words for carbon reduction on the energy consumption side, one is substitution and the other is reconstruction.. The so-called substitution is to replace traditional coal, oil and gas with non-carbon energy sources such as green electricity, green hydrogen and geothermal, while reconstruction emphasizes that a series of technological processes need to be re-established in the process of substitution.

In this regard, we can be divided into nine areas, the energy consumption side of the low-carbon research and development of the technology or alternative methods to make a brief introduction.

1. The construction sector should work in three areas. The first is to make energy-saving transformation of the building itself; the second is for urban building energy, including heating/cooling and household cooking, etc., should be based on green electricity and geothermal; rural household energy, can use roof photovoltaic shallow geothermal living biogas solar collector external green electricity comprehensive complementary way.

2. The transport sector can focus on five areas. In the future, private cars will be dominated by pure electric vehicles. Heavy trucks and long-distance passenger transport can be dominated by hydrogen fuel cells. Railway transportation is mainly electrified. Hydrogen fuel cells can be used in special terrain and sections, and maglev high-speed trains can be developed at the same time. Batteries can be used for inland shipping in the shipping industry, and hydrogen fuel cells or liquefied natural gas with relatively low carbon dioxide emissions can be used for long-distance navigation.

3. Carbon emissions from the steel industry mainly come from coking and coke-making, which can be low-carbon in two stages.. The first stage is to make full use of the waste heat and residual energy of coke ovens and blast furnaces, and at the same time make full use of the by-products in the steelmaking blast furnaces by means of tempering co-production. The second stage is to gradually replace the traditional process with a new low-carbon process, develop and improve the oxygen-enriched blast furnace steelmaking process, use green hydrogen as a reducing agent to replace coke in the steelmaking process, and use short-process clean steelmaking technology for scrap rerefining.

4. The emissions of China's building materials industry mainly come from the production of cement, ceramics and glass, of which 80% come from cement.. Low carbonization in building materials industry should develop technologies from three aspects. First, calcium carbide slag, fly ash, steel slag, calcium silicate slag and various kinds of slag should be used instead of limestone as raw materials for calcined cement to reduce the possibility of carbon emission from raw material utilization. Second, when calcining cement, green electricity, green hydrogen and biomass should be used to replace coal as much as possible. The third is to use green electricity as energy to produce ceramics and glass.

5. Chemical emissions from two major aspectsOne is the use of coal and natural gas as energy in the production process, and the other is the "carbon reduction" when coal, oil and gas are used as raw materials to produce chemical products. For example, the production of ethylene from coal requires hydrogenation to reduce carbon. If the added hydrogen is not green hydrogen, there will be carbon emissions, and the reduced carbon will generally be emitted into the atmosphere as carbon dioxide. Therefore, the chemical industry's low-carbon should start from four aspects, one is distillation, roasting and other processes with green electricity, green hydrogen; two is to make full use of waste heat, residual energy; three is the appropriate control of the scale of coal chemical industry, conditions permit as far as possible with natural gas as raw material; four is the carbon dioxide capture-utilization processing.

6. Carbon emissions in the non-ferrous industry mainly come from the two processes of mineral processing and smelting.In the entire metallurgical industry emissions, the aluminum industry emissions accounted for more than 80%, because the electrolytic aluminum process uses carbon as the anode, carbon in the electrolysis process will be oxidized into carbon dioxide emissions. Therefore, the low-carbonization of the metallurgical industry is to use green electricity as much as possible in the process of mineral processing and smelting; the second is to develop green materials to replace the carbon anode in the electrolytic cell; the third is to make energy-saving transformation of the electrolytic cell itself; the fourth is to recycle aluminum scrap metal.

7. In other industrial fields, food processing industry, paper industry, fiber manufacturing industry, textile industry, pharmaceutical industry, etc. also have a certain amount of carbon emissionsThere are two main sources of its emissions, one is the coal, oil, and gas used in the production and processing process, and the other is the emissions from its waste. The low-carbon transformation of these industries mainly lies in replacing fossil energy with green electricity, and at the same time doing a good job in recycling and reusing waste.

8. The service industry is a huge area, but the service industry is dominated by "indirect emissions".That is, electricity consumption in the service industry is generally counted in the carbon emissions of the power system, oil consumption in the transportation process is generally counted in the traffic emissions, and energy consumption in buildings (including gas consumption in the catering industry) is counted in the building emissions. It seems that the amount of "direct emissions" is not large. But this does not mean that the service industry can stay out of the low-carbon business. On the contrary, the service industry can also "take the initiative". On the one hand, it is to do a good job in energy conservation, and on the other hand, it is to use electricity as much as possible to replace the use of fossil energy.

9. Carbon emissions from agriculture mainly come from the use of agricultural machineryAt the same time, livestock breeding in agriculture as well as planting is methane (CH₄), nitrous oxide (N₂O) is the main source of emissions, and the greenhouse effect capacity of the two is tens to hundreds of times that of the same equivalent carbon dioxide. Starting from this premise, the low-carbonization of agriculture is that agricultural machinery uses green electricity and green hydrogen instead of diesel as power; the second is to excavate technologies that can reduce methane and nitrous oxide emissions without affecting crop yields from the perspective of field management; The third is to develop technologies to reduce carbon emissions from animal husbandry; the fourth is to increase the carbon content of agricultural soil as much as possible.

According to the introduction of these nine aspects, we can see:In theory, it is not difficult to replace coal, oil and gas with green electricity and green hydrogen at the energy consumption end, but the reconstruction of technology and equipment is by no means a simple matter.. At the same time, we can also imagine that such replacement and reconstruction will certainly increase the cost of final consumer goods. So it takes time to replace and rebuild.

When we think of carbon sequestration, the first thing we think of is the natural process of absorbing and fixing carbon dioxide in the atmosphere through the ocean and land surface. However, it must be pointed out here that human activities emit carbon dioxide into the atmosphere every year, part of which can be absorbed by natural processes, and if the remaining part is not fixed by human means, the concentration of carbon dioxide in the atmosphere will increase year by year.So when we talk about carbon sequestration, we mainly refer to the part that is fixed through human efforts.The earth's natural carbon sequestration process is a "heavenly help" and is difficult to attribute to specific countries or entities.

"Human efforts" to sequester carbon can generally be divided into two major ways, one is the conservation and restoration of ecosystems, and the other is to capture carbon dioxide, or process it into industrial products, or bury it in the ground or seabed. The second aspect is often talked about "carbon capture, utilization and storage"-- CCUS(Carbon Capture and Utilisation-Storage)。

The public is familiar with carbon sequestration in ecosystems. It uses plant photosynthesis to absorb carbon dioxide in the atmosphere. Part of the absorbed carbon is stored in the plants themselves for a long time (such as tree trunks), and part of the absorbed carbon is stored in the soil for a long time in the form of organic carbon after decay (such as leaves). Of course, organic carbon is also partially converted into inorganic carbon and combined with calcium ions in the surface system to form limestone. Although the types of surface ecosystems are diverse, the forest ecosystem really plays a major role. This is because all kinds of trees in the forest have a long growth period. In the age-appropriate period of the trees, the carbon sequestration can be carried out continuously. When the trees enter the mature period, the carbon sequestration ability will be weakened, but people can continue to maintain the positive carbon sequestration through felling and reforestation, the felled wood can be made into furniture and other products, so as not to quickly return the carbon fixed over the years to the atmosphere.

Therefore, the focus of carbon sequestration in the ecosystem lies in the forest ecosystem, and the management of the forest ecosystem lies in the conservation and the expansion of the area.. my country has a large number of mountainous areas suitable for forest growth. The ecology of these areas has been damaged to a large extent in the past. In recent decades, they have been recovering. These artificial secondary forests or arbor/irrigation mixed forests are very "young". Potential for further development and carbon sequestration. At the same time, China has a lot of non-agricultural land can be used for afforestation, including coastal beach planting mangroves, urban and rural green land planting trees. Therefore, ecosystem construction will play a vital role in the process of achieving carbon neutrality in China.

Another way of artificial carbon sequestration is CCUS, which includes carbon capture technology, industrial utilization technology after capture (divided into biological utilization and chemical utilization), geological utilization and storage technology. For these technologies, at home and abroad is still in the research and development stage, the real large-scale application has not yet seen.

Carbon capture technology is divided into three categories. One is the chemical absorption method, which uses chemical absorbents to generate salts with carbon dioxide in flue gas, and then heats or reduces pressure to release and collect carbon dioxide. The second is the adsorption method, which is subdivided into chemical adsorption method and physical adsorption method. Chemical adsorption method is to use the adsorption material with carbon dioxide molecules for chemical bonding, and then change the conditions of carbon dioxide molecules desorption and collection; physical adsorption method is the use of activated carbon, natural zeolite, molecular sieve, silica gel and other carbon dioxide in flue gas for selective adsorption and then desorption recovery. The third is the membrane separation method, which uses the different permeability of the membrane to the gas molecules to achieve the purpose of separating and collecting carbon dioxide. In terms of specific operations, carbon capture can also be divided into pre-combustion capture, post-combustion capture, chemical chain combustion capture, biomass energy carbon capture, direct capture from the air and other technologies.

There are currently four main categories of industrialized bio-utilization technologies after carbon capture.One is the use of carbon dioxide to produce microalgae in reactors, which are reused as raw materials for the production of fuels, fertilizers, feed and chemicals. The second is to inject the captured carbon dioxide into the greenhouse to increase the photosynthesis of crops in the greenhouse. This process can also be called carbon dioxide fertilization. The third is to combine carbon dioxide with the microbial fermentation process to generate organic acids. Four is the use of carbon dioxide for the synthesis of artificial starch. The industrial chemical utilization after carbon capture is divided into two major technical approaches. One is to reduce the tetravalent carbon in carbon dioxide, add methane, hydrogen and other gases, and then integrate them into methanol, olefins, refined oil and other products. Another major category is non-reducing technology, including carbon dioxide plus ammonia to make urea, phenol to synthesize salicylic acid, methanol to synthesize organic acid esters and other technologies, as well as synthetic degradable polymer materials, various polyester materials and other technologies.

There are also many types of geological utilization technologies. Some of these technologies have been in the industrialization demonstration, and some are still in the laboratory exploration stage. For example, the collected carbon dioxide is used to drive oil, coalbed methane, natural gas, shale gas, etc., which belong to the application of oil and gas exploitation. One common feature of this technology is to press supercritical carbon dioxide into the formation through productive drilling, and use it to drive the oil and gas in pores and fractures to flow out of exploitable drilling, so as to increase oil and gas production or increase oil and gas recovery rate. At the same time, carbon dioxide is retained in the pores, cracks in the long-term storage. This kind of technology has been demonstrated in industrial applications at home and abroad. Other technologies are in the process of exploration, such as geothermal heat in hot dry rock. Dry hot rock is buried at a depth of several kilometers, and there is basically no fluid inside it, and the temperature is above 180 ℃. To exploit the heat energy in dry hot rock, it is necessary to drill production wells and increase cracks in the rock by means of fracturing, then the working medium is injected into the production wells to allow them to flow and collect heat, and finally the heat is collected from the mining wells. Some studies have shown that using carbon dioxide as a working medium can not only play the role of mining hot dry rock heat, but also seal part of the carbon dioxide underground.

Geological storage technology is to collect carbon dioxide directly through the borehole into the deep underground or into the deep seawater. In particular, it should be noted that the deep sea has a huge capacity to dissolve and preserve carbon dioxide.

In short, there are many technologies for carbon sequestration, but these technologies inevitably require additional energy to be added, so they have the potential to increase the cost of the final product by a large amount.. As for geological storage, although it is feasible in theory and practice, it seems to be "idling. At this stage, only ecological solid can take into account economic and social benefits.

Achieving carbon neutrality is a long-term process. It requires a plan to guide the overall work, and according to the development of the situation and technological progress, a working mechanism that can continuously improve the plan can be formed.. China's goal is to achieve carbon neutrality by 2060. Obviously, at the current level of cognition, it is not realistic to make a plan that can cover nearly 40 years. However, one thing we must know from the beginning is how much carbon dioxide our country can emit, or how much carbon dioxide emissions can be reduced from the current carbon dioxide emissions of about 10 billion tons before we can announce the completion of the carbon neutrality target.

This question is not easy to answer exactly, but the idea of finding the answer is available, that is"Emissions = Ocean uptake Ecosystem carbon sequestration Anthropogenic carbon sequestration Other surface processes carbon sequestration"this formula. We can analyze this item by item.

In the past few decades, the ocean has absorbed 23% of man-made carbon dioxide emissions. This process is relatively stable. Although it is difficult to predict whether there will be major changes in the future, it is assumed that the ocean will maintain this absorption ratio. There is a basis.

The carbon sequestration capacity of terrestrial ecosystems in China is very strong. According to relevant research, the annual carbon sequestration of China's terrestrial ecosystem from 2010 to 2020 is 1 billion -1.3 billion tons of carbon dioxide. According to this set of data and comprehensive analysis using various models, some experts predict that the carbon sequestration capacity of China's terrestrial ecosystem in 2060 will be 1.072 billion tons of carbon dioxide per year. If ecosystem management is enhanced, 0.246 billion tons of carbon dioxide per year can be added, that is, the total carbon sequestration potential of China's terrestrial ecosystem in 2060 is 1.318 billion tons of carbon dioxide/year. In addition, my country's offshore ecosystem carbon sequestration project has not yet started, and this area should also have greater potential.

As for the amount of carbon capture for industrial utilization and storage, it depends on the technical level and economic benefits, which is difficult to estimate at present. But we can also assume that if there is a "gap" in carbon neutrality by then, the government will subsidize man-made industrial carbon sequestration and strive for industrial carbon sequestration and geological sequestration of 0.3 billion -0.5 billion tons of carbon dioxide per year. At the rate of China's industrial technology development, this assumption is still relatively "conservative.

Carbon sequestration in other surface processes refers to the groundwater system converting organic carbon into limestone precipitation, and soil erosion burying organic carbon in the river-lake system. At present, there is no systematic research data on the total amount of carbon that can be fixed in a year, but the rough estimate is about 0.1 billion tons of carbon dioxide.

For this reason, we can make such an analysis. If China's annual carbon dioxide emissions are about 2.5 billion tons around 2060, then the ocean can absorb 25 × 23%= 0.575 billion tons of carbon dioxide, land and offshore ecosystems can sequester 1.4 billion tons of carbon dioxide, and industrial carbon sequestration and geological sequestration of about 0.4 billion tons of carbon dioxide can basically achieve "net zero emissions". Of course, it is also very difficult to reduce carbon dioxide emissions from 10 billion tons to 2.5 billion tons, which requires us to have a macro rough line plan first. According to the practice of China's five-year plan, we can consider two five-year plans as one stage, divided into four stages, and achieve the goal of carbon neutrality in 40 years.

The first step is the "carbon control phase", striving to control the total carbon emissions within 10 billion tons by 2030, that is, during the "14th Five-Year Plan" period, it will be a little more than the current one, and during the "15th Five-Year Plan" period, it will be reduced again.. In this first decade, the transportation sector has strived to substantially increase the proportion of electric vehicles and hydrogen energy transportation, the construction sector has strived to complete about half of the low-carbon transformation, and the industrial sector has mostly completed research and development and demonstration of the process of replacing coal with coal, hydrogen and electricity. The growth of electricity demand in the past ten years should be met with as little thermal power as possible, but should be mainly wind and light. Inland nuclear power should complete the application demonstration, and the hydrogen production and hydrogen use system should be completed and popularized.

The second step is the "carbon reduction phase", striving to control the total carbon dioxide emissions within 8.5 billion tons by 2040.. At this stage, we will strive to basically complete the low-carbon transformation of the transportation and construction sectors, and the industrial sector will comprehensively promote the process of replacing coal with coal/oil/natural gas + hydrogen + electricity, and promote new carbon-free processes in technically mature areas. In this decade, the total installed capacity of thermal power will strive to eliminate 15% of backward production capacity, and the system of hydrogen production and hydrogen production from wind and light resources will be complete and the production capacity will be greatly expanded.

The third step is the "low-carbon phase", striving to control the total carbon dioxide emissions within 6 billion tons by 2050. At this stage, the construction sector and the transportation sector reached nearly no carbonization, and the low-carbon transformation of the industrial sector was basically completed. In the past ten years, the total installed capacity of thermal power has been reduced by another 25%. Wind, photovoltaic power generation and hydrogen production are the main energy sources, and the economically applicable energy storage technology is basically mature. It is estimated that my country's nuclear waste recycling technology will basically mature at this stage, and the on-grid electricity price of nuclear power will decline. Therefore, the conditions for replacing thermal power with nuclear power as a "stable power source" will basically be met.

The fourth step is the "neutralization stage", and strive to control the total carbon dioxide emissions at 2.5 billion -3 billion tons by 2060.. At this stage, an intelligent and low-carbon power supply system has been established. The installed capacity of thermal power only accounts for about 30% of the current total, and part of thermal power uses natural gas to replace coal. Thermal power emissions strive to be controlled at 1 billion tons per year. Thermal power is only used as emergency power. For the "basic load" of some areas, the main power supply is light, wind, nuclear, and water. In addition to the transport and construction sectors, the industrial sector is also fully low-carbon. There are still 1.5 billion tons of carbon dioxide emission space, which is mainly allocated to cement production, chemical industry, certain raw material production and industrial processes, and domestic energy consumption in remote areas. The remaining 0.5 billion tons of carbon dioxide emissions space mobile distribution.

The "four-stage" road map is only a rough expression. Due to the non-linear nature of technological progress, the so-called ten-year period is only set for convenience of expression.

From the previous introduction, we can see that the realization of carbon neutrality can be understood as a great change in the mode of economic and social development, which is a great challenge for any country in the world today. For my country, the main challenges lie in the following areas.First, China's energy endowment is dominated by coal.. In the three fossil energy sources of coal, oil and gas, the same amount of heat is released, and the amount of carbon dioxide emitted by coal is much higher than that of natural gas, and it is also much higher than that of oil. China's power generation has long been dominated by coal, which is a resource disadvantage compared with those developed countries in Europe and the United States where oil and natural gas account for a high proportion of thermal power.Second, the scale of China's manufacturing industry is very large.. As we mentioned in the previous introduction, nearly 70% of China's carbon dioxide emissions come from industry, which is much higher than that of developed countries in Europe and the United States, which is related to the high proportion of China's manufacturing industry and its status as a "world factory.Third, China's economy and society are still in the stage of compressed and rapid development.There is a huge demand for urbanization, infrastructure construction, and improvement of people's living standards.. Fourth, China's energy demand is still growing, which means that China's carbon dioxide emissions will continue to grow both in total and per capita. Fifth, there are only 30 years after China reaches its peak in 2030 and 2060, while the United States, France and the United Kingdom have reached their peak in the 1970 s from the perspective of per capita carbon emissions. They have an adjustment time of 80 years from the peak to the neutralization in 2050.

In order to clarify the challenge of carbon neutrality to our country more clearly, we will use several sets of carbon emission-related data to further illustrate it in an international comparison. The first set of data is the cumulative carbon dioxide emissions (in billions of tons of carbon dioxide) of different countries from 1900 to 2020. The United States is 4047, the EU 27 is 2751, China is 2307, Russia is 1152, and Japan is 655., The United Kingdom is 618, India is 545, Mexico is 201, and Brazil is 156. This cumulative emission can slightly indicate the "family wealth" accumulated by a country for a long time, but such statistics do not take into account the population base, so we need the second set of data, the cumulative per capita emission from 1900 to 2020. This set of data takes the country as a unit, divides the annual national emission by the population, and obtains the annual per capita emission, add up the per capita emissions over the past 120 years (the data are in tons of carbon dioxide), specifically: US 2025, Canada 1522, UK 1209, Russia 848, EU 27 713, Japan 575, Mexico 295, China 190, Brazil 107, India 58, the global per capita cumulative is 375, China so far only half of the global per capita, less than one tenth of the United States.

The third set of data is the current emissions by country (in billions of tons of carbon dioxide), specifically: China 100, the United States 52, the EU 27 30, India 25, Russia 16, Japan 11. If you consider per capita, then there is a fourth set of data (per capita emissions from 2016 to 2020, in tons of carbon dioxide), specifically: US 15.9, Canada 15.3, Russia 11.4, Japan 9, China 7.2, EU 27 6.6, Brazil 2.3, India 1.9. From the above four sets of data, it can be seen that China's development in recent decades has the characteristics of compression, so the current per capita and country-specific emission data are relatively high, which is also the so-called "reason" for the Western media, which has the right to speak, to constantly put on China as the "largest emitter" or even the "largest polluter". However, if we look at the cumulative per capita emissions, China's "contribution" to the world is very small. In addition, my country's per capita GDP has reached the global average, and the cumulative per capita emissions are only half of the world. This is still achieved on the basis that my country's energy is dominated by coal and a large number of annual net exports of manufacturing products. This shows that my country is by no means What some researchers call an "energy resource consuming" economy.

The fifth set of data is very interesting. It is the per capita consumption of carbon emissions established by the International Energy Agency and the World Bank. It takes into account the "carbon emission transfer" between countries through import and export ". The data from 2018 to 2019 are as follows (in tons of carbon dioxide): 15.4 in the United States, 7.6 in Germany, 7.5 in Canada, 7.4 in Japan, 7.0 in Russia, 5.7 in the United Kingdom, 4.4 in France, 2.7 in China, 1.5 in Brazil and 1.1 in India. This set of data shows that some countries in the world are only "survival carbon emissions", while some countries have already entered the ranks of "luxury" or "waste" countries!

Earlier we talked about the five challenges of carbon neutrality to China, and now we talk about five opportunities.. First, my country's photovoltaic power generation technology is already "one riding the dust" in the world. Wind power generation technology is in the first square in the world, nuclear power technology has also entered the world's advanced ranks, and the level of building hydropower stations is unparalleled. Second, there are a large number of wind and light resources in western China, especially in the desert and Gobi areas in the west, which are ideal places for the construction of photovoltaic power stations, and the construction of photovoltaic power stations can also bring ecological benefits; in the east, we have a large area of flat continental shelf, which can provide a large number of places for offshore wind power construction. Third, most of China's forests are in their infancy, and there are still a lot of afforestation areas. In addition, the carbon in grassland, wetland and farmland soil is mostly in an unsaturated state, so the carbon sequestration potential of the ecosystem is very large. Fourth, the process of achieving the goal of carbon neutrality is also a process of greatly reducing the emission of environmental pollutants, which means that we will completely solve the problem of air pollution, and the emission of other pollutants will also be substantially reduced. In addition, carbon neutrality also means that we will achieve energy independence, domestic crude oil and natural gas will be able to meet the needs of chemical raw materials, imported oil and gas will be greatly reduced, and the so-called "Malacca dilemma" will no longer be a substantial threat. Energy independence will also contribute to food security to some extent. Fifth, my country's national system advantages will play a major role in the process of carbon neutrality, because carbon neutrality involves a large number of national planning, industrial policies, financial and tax policies, etc., and it needs to really play a game of national chess. We can see this from the course of promoting the photovoltaic industry in our country, and such experiences will continue to be summarized and deepened in the future. We can even expect that even those countries that adhere to free market economies will be helped in the design of national industrial policies if they want to be truly carbon neutral.