From the perspective of emission reduction, the control of carbon emissions can be divided into two categories: one is absolute amount control; the other is relative amount control. The two methods are described below:
(1) Absolute quantity control
Absolute quantity control is total quantity control. Total control is not only an idea of environmental management, but also a means of environmental management. Total control can be divided into three types: target total control, capacity total control and industry total control. The total target control means that under the condition of a certain total carbon emission target, the carbon emissions and carbon emission reductions allowed in each region should be carried out in an optimal way according to the level of pollutant discharge and the feasibility of economic technology in each region. distribute, and continuously reduce carbon emissions in various regions to achieve the goal of reducing total carbon emissions. The total capacity control is based on environmental quality standards, and the total amount of carbon emissions is allocated from the controllability of pollution sources and the accessibility of environmental goals. That is, this type of control is based on an accurate quantification of the environment’s own pollution-holding capacity. The total amount control of the industry is based on the rational use of energy and resources as the control basis, and the total amount of carbon emissions is allocated based on the best production process and treatment technology.
It can be seen that although the purpose of various methods of absolute carbon emission control is to reduce carbon emissions from the total amount, the total amount of carbon emissions allowed and the process of emission reduction are different. In terms of the total amount of carbon emissions allowed, the total amount of carbon emissions allowed in the target total amount control method is determined according to different established targets and is a target allowable amount. The total amount of carbon emissions allowed in the total capacity control method is determined according to the environmental carrying capacity, which is an environmental carrying capacity; the total amount of carbon emissions allowed in the industry total control method is determined according to the most efficient production technology in the industry, which is a technically accessible amount. From the perspective of the process of emission reduction, the three types of total amount control optimize the distribution of the total amount of carbon emissions among various emission subjects according to different principles. The target total amount control method allocates regional carbon emissions based on the existing emission levels and emission reduction technologies in each region. This actually ensures the normal level of economic development in various regions at the current stage, and at the same time allocates more emission reductions to regions with advanced emission reduction technologies and high emission reduction efficiency. The total capacity control method is to allocate carbon emissions according to the environmental carrying capacity of each region and the controllability of emission sources, so that the carbon emissions obtained by each subject will not exceed the environmental capacity. The industry total control method is to allocate carbon emissions based on the most effective production technology to ensure that carbon emissions resources flow to the enterprises with the highest production efficiency in the same industry.
Various methods of absolute quantity control have their applicable scope and restrictive conditions of use. The target total amount control method is easier to grasp the total amount of carbon emissions; the capacity total amount control method can not only protect the environment when the environmental carrying capacity is known, but also make full use of carbon emission resources to promote economic and social development, but the definition of environmental carbon emission capacity is often restricted by the existing technical level, and it is difficult to achieve precise quantification. The way of total industry control can prompt enterprises to improve production technology, improve energy efficiency, and reduce carbon emissions. However, because advanced production technology is often kept secret, it is difficult to truly determine the most efficient production in the industry.
Therefore, relatively speaking, the control method of the target total amount is easier to operate. The saving policy, compensation policy, bubble policy and EU emission trading scheme implemented in the United States, as well as China’s “Tenth Five-Year” environmental protection plan and “Eleventh Five-Year” environmental protection plan have all adopted the method of target total amount control.
The most successful absolute control program at this stage is the “Kyoto Protocol”. The “Kyoto Protocol” requires the world’s major industrial countries to reduce carbon dioxide emissions by an average of 5.2% in 2008-2012 compared with 1990 emissions. And this book also proposes three mechanisms to achieve this goal: carbon emissions trading mechanism, clean development mechanism and joint implementation mechanism.
The carbon emissions trading mechanism allows carbon trading among developed countries, and countries that are difficult to complete the task of reduction can purchase carbon emission credits from countries that have exceeded the task; the Clean Development Mechanism allows developed and developing countries to conduct carbon trading, and developed countries can offset corresponding greenhouse gas emissions by providing green technologies or equipment to developing countries; the joint implementation mechanism is only for the EU, and only requires the EU to complete the emission reduction task as a whole, regardless of the emission reduction process of individual countries.
(2) Relative quantity control
Relative quantity control is a method of linking carbon emissions with certain indicators of the economy and society, so as to achieve the purpose of not only controlling carbon emissions but also achieving other goals in the economy and society. The most commonly used is the carbon intensity control method, that is, the control of carbon emissions per unit of GDP, which closely links carbon emission reduction and economic growth. In 2003, the Bush administration first proposed a carbon intensity control method, which reduced greenhouse gas emissions per million US dollars of gross domestic product by 18% from 2002 to 2012. At the Copenhagen Conference in 2009, China also made a commitment to reduce carbon intensity by 40%-45% by 2020 on the basis of 2005.