On September 22, 2020, China made a public commitment: strive to reach peak carbon dioxide emissions by 2030 and strive to achieve carbon neutrality by 2060. China has a clear and specific roadmap for carbon peaking and carbon neutrality, which not only assumes China's environmental responsibility as a major country, but also sets these two goals to allow all Chinese people to live in a cleaner environment and breathe cleaner air .
As early as the end of 2019, my country stated that China has achieved the goal of reducing carbon emissions by 2020 ahead of schedule. This time, we have made the amazing promise of "carbon neutrality". How will we achieve this goal? Where does our confidence come from? listen to me slowly...
What is carbon neutrality?
Achieving carbon neutrality requires increasing carbon sinks while reducing emissions
Simply put, carbon neutrality means that carbon emissions minus carbon uptake (carbon sinks) equals zero. We need to "open source and reduce expenditure" in our economy, and carbon neutrality is about "reducing emissions and increasing sinks"! To understand carbon neutrality, we must first understand what a carbon sink is. Carbon sinks refer to the storage of carbon-containing compounds through natural or artificial means, thereby reducing the concentration of carbon dioxide in the atmosphere.
Since global warming became a consensus, people from all walks of life have deepened their understanding of the concept of carbon sinks. Carbon sinks can be divided into three categories: ocean carbon sinks, terrestrial vegetation, and artificial technologies. Terrestrial vegetation and ocean carbon sinks are the two most important carbon sinks in nature. About half of the carbon dioxide emitted by human activities every year is stored in these two natural carbon sinks. It is obviously a very smart idea to make a fuss about the natural carbon sinks. In mid-April 2018, a number of Chinese scientists published 7 papers in international academic journals at the same time, introducing the good ecosystem China is trying to create from various aspects, and the key words revolve around carbon sinks and carbon pools. This seems to be telling the world: we are coming prepared!
What other artificial means of absorbing carbon are there?
In recent years, the research on "artificial carbon sinks" has also begun to deepen. The following are the mainstream ones:
chemical absorption adopts chemical absorption method (such as ethanolamine, etc.) The carbon dioxide produced by the factory is captured.
To sequester carbon, either by planting trees, by converting carbon dioxide into solids such as minerals, or by injecting carbon dioxide into the ground
Deep sea storage As mentioned earlier, since the ocean is a huge carbon sink, why not inject carbon dioxide into the deep sea? Under high pressure on the seafloor, carbon dioxide will turn into a liquid, forming solid clathrate hydrates with water. The problem is that there is a potential risk in this approach. If a leak occurs, it will cause acidification of the seawater, which will cause unpredictable ecological disasters, so some countries have reached a consensus not to allow deep-sea storage of carbon dioxide. In addition, some researchers pointed out that burying carbon dioxide deep on the seafloor may "squeeze" methane out of the flammable ice on the seabed. Pros and cons can come at the same time. You must know that the greenhouse effect of methane is much more powerful than that of carbon dioxide.
Injecting the Oil Field Injecting carbon dioxide directly into the oil field to "squeeze out" the crude oil. This technology has a history of more than 40 years, and it was first used to improve the efficiency of oil collection. However, carbon dioxide will dissolve in crude oil and will be released after combustion, which cannot achieve the purpose of carbon neutrality.
Underground storage Injecting carbon dioxide into mined oil fields has inspired scientists to inject carbon dioxide into some sealed geological structures and store them.
Biodegradation The carbon dioxide is degraded by microorganisms. This work can be done in conjunction with the previous method, which is to first store carbon dioxide in the ground and inject carbon dioxide-degrading microorganisms at the same time.
Minerals absorb carbonate in a lower energy state than carbon dioxide, that is to say, in the geosphere, carbon dioxide will eventually be converted into carbonate. As long as humans accelerate this process, carbon dioxide in the air can be greatly reduced. Thermodynamically, minerals such as olivine (magnesium silicate, ferrous silicate) and serpentine (hydrated magnesium silicate) can react with carbon dioxide to form magnesium carbonate.
Artificial carbon sinks have their own advantages and disadvantages. For some mature artificial carbon sinks, we should boldly apply them, while for some immature technologies, we should take a wait-and-see attitude and observe the follow-up effects through enough experiments. In particular, it should be noted that the vision should not be limited to one point, but to look at the problem from the entire industry chain. For example, ethanolamine is used to absorb carbon dioxide, and the carbon dioxide of thermal power plants is indeed absorbed, but the carbon emissions of producing ethanolamine, the supporting facilities for developing these technologies, and the method of storing the absorber must be taken into account.
Judging from the current operating costs and operability, artificial carbon sinks are far from being compared with natural carbon sinks. Planting trees honestly is still the mainstream at present.
Underground Carbon Sequestration Solutions
Everyone is equal in the face of carbon emissions
After talking about carbon sinks, let's look at carbon emissions. In the past, the use of energy was basically equivalent to carbon emissions. That is to say, when fossil fuels occupy the main body of primary energy, if we want to enjoy a better life, we need to use more fossil fuels and accordingly emit more carbon dioxide. This is what Academician Ding Zhongli meant when he regarded carbon emissions as the "right to development".
In fact, in terms of emission reduction, developed countries have also taken action. For example, in 2019, the United Kingdom proposed a plan to "achieve zero carbon emissions by 2030". However, we have to question the specific method. For example, "converting natural gas into clean hydrogen energy" is very confusing: natural gas is methane, a kind of hydrocarbon. After getting hydrogen, where does the carbon go? This is nothing more than based on a carbon transfer. The technologies of the United States and the United Kingdom for hydrogen production from natural gas are already very mature, but in order to achieve zero carbon emissions, their countries leave the process of converting natural gas to developing countries. In this way, they just enjoy "clean hydrogen energy" and let developing countries emit a large amount of carbon dioxide, causing environmental pollution in these countries, which is obviously irresponsible.
China is a responsible big country. We pay attention to a community with a shared future for mankind. We must be responsible for the country, the people, future generations and even all mankind. Therefore, we have taken concrete and practical measures to save energy, reduce emissions, and protect the environment. In 2016, my country's commitment included one: "By 2030, increase the proportion of non-fossil energy in total primary energy supply to around 20%."
Use new energy to change the energy structure
In 2019, my country's energy structure: coal (58%), oil (20%), natural gas (8%), hydropower (8%), nuclear energy (2%), and other renewable resources (4%). The first is hydropower. China has the largest hydropower reserves in the world. It would be a pity not to use it. In addition to the Three Gorges, we have already deployed a lot in the southwest region. It should be pointed out that the Wudongde Hydropower Station was officially put into operation in June 2020. In recent years, my country's hydropower industry has made great strides.
Then there is nuclear power. Although nuclear power is controversial, proponents believe that nuclear power is a clean energy source, and opponents have more practical reasons: historically there are the Three Mile Island in the United States, the Chernobyl nuclear accident in the Soviet Union, and in recent years, the Fukushima nuclear accident in Japan leakage. However, my country attaches great importance to the safety of nuclear power, and has taken effective protective measures. The nuclear power business has been developing steadily without incident, which gives us more confidence to develop China's nuclear power business. There are also very successful experiences abroad. For example, the proportion of nuclear power in France has reached as high as 80%. The United States, Russia, the United Kingdom and other major countries have also stated that they will not stop the pace of nuclear power development because of the Fukushima accident. Therefore, my country's nuclear power industry may continue to advance steadily, but nuclear energy cannot replace fossil energy in the short term.
Lastly is photovoltaics. Since overtaking Germany in 2015, China's photovoltaic industry has been far ahead. At the end of 2019, the total installed capacity of photovoltaic panels in China exceeded 200 GW, and now the world's largest solar power plant is the 850 MW Longyangxia Dam Solar Park in my country. Our country’s goal is to reach 1,300 GW of installed solar capacity by 2050. Of course, compared with developed countries such as Germany, Japan, and Australia, the per capita potential of solar energy in my country is still very high. At present, there is still a lot of room for optimization in the design of photovoltaic power plants. It is believed that after some key technological breakthroughs, China's photovoltaics can further expand rapidly.
my country has made considerable preparations in hydropower, nuclear power and photovoltaics. Therefore, if we can achieve a substantial adjustment of the energy structure, and the "troika" of hydropower, nuclear power and photovoltaics will increase non-fossil energy from the current 15% to more than 30%, then "energy utilization and cost are equivalent to The phrase "carbon emissions" is not necessarily 100% based on fossil fuels as energy sources.
In addition, China is also actively exploring the field of nuclear fusion. In 2018, the China Fusion Engineering Experimental Reactor (CFETR for short) started construction in Hefei. According to public information: CFETR plans to go in three stages to complete the "Chinese fusion dream". In the first stage, by the end of 2021, CFETR will start the project construction; in the second stage, by 2035, it is planned to build a fusion engineering experimental reactor and start large-scale scientific experiments; in the third stage, by 2050, the fusion engineering experimental reactor will be successfully tested and a commercial demonstration of fusion will be built. Heap to complete the ultimate human energy. If my country can successfully achieve nuclear fusion in 2050, the pressure to achieve carbon neutrality in 2060 will be greatly reduced.
At that time, human beings will acquire energy that is inexhaustible and inexhaustible to some extent. In order to develop the next generation of cleaner nuclear fusion technology, the Earth-Moon Economic Zone will also be officially put on the agenda, and helium-3 on the moon will become a valuable resource for mankind.
At one time, global warming was considered by a considerable number of people to be a "conspiracy theory", and some even believed that it was a conspiracy by developed countries to deprive us of our "right to development". Ding Zhongli's "Are Chinese people human?" has become a "question of the soul"! For the survival and development of human beings, and for people all over the world to live a good and happy life, we should respect scientific facts and use our wisdom and sweat to create a better tomorrow. Fortunately, quite a few of us wise and brave have made wise choices.
Today, in the field of new energy and carbon neutrality, countless workers are working silently and steadily. After 40 years, we are waiting for a new era of "green economy". For 5,000 years, isn't that how the Chinese have come step by step?
Achieving carbon neutrality requires multiple approaches
Although the road to carbon neutrality is still long, China will usher in a greener future
(This article was originally published in Zhihu)
Why are there so many trees in China?
Planting trees = increasing foreign exchange
According to satellite data in a NASA report released in 2019, China and India are leading the growth of land greening, with the impact mainly from China's ambitious tree-planting program and intensive agriculture in both countries.
Since they have been seen by satellites, it shows that my country's greening has achieved good results. In October 2020, an article by Liu Yi's team was published in the world's authoritative natural science journal "Nature". In the article, they counted the data from 6 observation points between 2009 and 2016, and found the following findings:
1. From 2010 to 2016, China's terrestrial ecosystems absorbed about 1.11 billion tons of carbon annually, absorbing the national average during the same period. 45% of man-made carbon emissions.
2. Carbon sinks in Southwest China (Yunnan, Guizhou, Guangxi, etc.) and Northeast China (especially Heilongjiang and Jilin) were previously severely underestimated.
3. my country's artificial afforestation has achieved remarkable results. In the past 10 to 15 years, each province (autonomous region) has increased the forest area by 400 to 4400 square kilometers each year, and at the same time has promoted the export of wood, and the domestic paper production has also increased. .
We have recognized that forests are the most important carbon sinks on the road to carbon neutrality, and their carbon storage capacity per unit area is 2.5 times that of farmland. According to research, every cubic meter of forest trees can absorb 1.83 tons of carbon dioxide on average. my country's Three-North Shelter Forest Program, launched in 1978, not only blocks sandstorms and allows the local soil to retain more water, but also stores a large amount of carbon dioxide from the atmosphere every year.
After the wood fiber is processed into granular solid fuel, it can be directly used for power generation, which can save a considerable amount of electricity and coal every year. In addition to direct combustion, biomass, such as wood-rich oils and starches, can be used to convert it into biodiesel or ethanol.