Mi Hong etc. Mode SELECTION OF CARBON EMISSIONS AND POLICY SIMULATION IN CHINA- BASED ON POSSIBILITY-SATISFIABiLITY DEGREE ANALYSIS OF CARBON EMISSIONS FOR THE PERIOD 2010-2050
Mode SELECTION OF CARBON EMISSIONS AND POLICY SIMULATION IN CHINA- BASED ON POSSIBILITY-SATISFIABiLITY DEGREE ANALYSIS OF CARBON EMISSIONS FOR THE PERIOD 2010-2050[(]
[MI Hong, Administration School, Zhejiang University, Hangzhou, P.R.C][1]
[Zhou Wei, Administration School, Zhejiang University, Hangzhou, P.R.C][2]
[Ma Pengyuan, Institute of Education, Xiamen University, Xiamen, P.R.C][3]
Preface
From 1978 to 2000, China's average annual growth rate of energy consumption was 4.1%, the economic growth rate over the same period was 9.7% (at constant prices), which had achieved the goal of "doubling of energy to ensure the quadrupling of economic output". But after 2002, energy consumption growth has significantly accelerated, that from 2002 to 2008, annual growth rate of energy consumption had reached 11%, while energy consumption almost doubled in just six years. Among them, 2003, 2004, 2005, these three years are the fastest growing period in this 30 years. The growth of energy consumption puts enormous pressure on domestic resources and the environment. High energy consumption caused by various forms of environmental destruction and pollution, which will eventually threaten the survival of mankind itself. Although the embodiment of environmental constraints on energy consumption is the economic loss and life health loss, in practice the constraint displays via fall-force machanism, that is: to reduce the environmental polluting and vandalistic, humankind should reduce the energy consumption. Under the premise of economy sum increase continually, per unit of output of energy consumption must reduce and improve energy efficiency.
To this end, our country had developed energy-saving and emission reduction programs, whose planning objectives are: until 2010, energy consumption per 10,000 RMB GDP should drop to below 1 ton of standard coal, compared to the 1.22 tons of standard coal in 2005, about 20% lower; unit water consumption of industrial added value reduced by 30%. In "Eleventh Five-Year Plan" period, the total discharge of major pollutants should reduce by 10%.By 2010, sulfur dioxide emissions should decrease from 25.49 million tons in 2005 down to 22.95 million tons, chemical oxygen demand (COD) should reduce from 14.14 million tons to 12.73 million tons. In addition, to optimize the energy structure, the proportion of nuclear energy and renewable energy should increase. By 2020, non-fossil energy sources would account for 15% of total energy consumption. In response to global climate change, the planning unit of output in 2020 should decrease by 40% -45% lower compared to 2005 carbon dioxide emissions. The key of reduce the energy and saving energy is reduce consumption per unit output value, which can be achieved though reduce the proportion of high energy-consuming industries, development and promotion of energy conservation technology and the development of the tertiary industry such as the representative of modern service industry. This paper chooses unit GDP energy consumption and per capita energy consumption to measure energy consumption level for energy consumption analysis of environmental constraints.
In November, 2008, a report from UNEP claimed that Beijing in China and its surrounding areas, the Yangtze River Delta and Pearl River Delta regions have been enveloped by brown cloud that has been shrouded with the ever-increasing global greenhouse gas intertwined with regional as well as being a significant impact on the global climate system. In the context of global warming, significant changes of the climate in China in recent hundred years have taken place. The main observations fact of climate changes in China conclude: First, in the past century, China's annual average temperature increased by 0.5 ℃ ~ 0.8 ℃, slightly higher than the average global warming over the same period, changes in recent 50 years is particularly evident; Secondly, for centuries, China's annual precipitation trend is not significant, but the volatile changes in regional precipitation is evident. China's average annual precipitation in the 20th century began to decrease after 50 years, with an average reduction of 2.9 mm every 10 years, but from 1991 to 2000 increased slightly. Third, in the past 50 years, China's major extreme weather and climate events is frequency and intensity of significant changes occurred. Drought in North China and Northeast China became more serious, and flooding in the Yangtze River region and the Southeast region increased. Since 1990, Annual precipitation in most years is higher than normal, and appears a type rain of dry in north and flood in south, drought and flood disasters occurred frequently. Fourth, in the past 50 years, China's coastal sea level rise rate of average 2.5 mm per year, slightly higher than the global average. Fifth, the mountain glaciers have fast retreated, and the trend is accelerating. In 2005, the area of desertification land in China is about 2.63 million square kilometers, accounted for 27.4% of the entire land area. Extreme weather events become more frequently, future climate warming will much more serious.
Overview
Because the historical period of China's industrialization is different from the developed countries', in which global fossil energy supply is inadequate and energy prices is higher than the price of developed countries in industrialization period, climate change and environmental pollution on human economic activities of restriction is more and more obvious. China must get rid of the current "high energy consumption, high discharge, high pollution" development pattern and then develop a "low energy consumption, low emissions, low pollution" resource conservation and environment friendly low carbon development mode.
From a justice perspective, China should take for less responsibility of global carbon emissions. However, in view of the consideration of reduction in meteorological disasters and curb domestic environment pollution, China must be active to cut back on fossil energy consumption in order to reduce emissions of carbon dioxide. With economic growth, China should gradually reduce energy consumption and reduce energy consumption growth strength, lower the speed and scale of energy, optimize the energy structure, reduce fossil energy, improve clean energy, reduce pollution and proportion of greenhouse gas emissions.
1. The multi-objective decision-making "possibility- satisfiability" methods principle
1.1 "Possibility- satisfiability" methods principle
In the decision-making process, the practical problems people met generally are considered from "demand" and "possibility" two aspects. The former reflects the subjective intention and expectation, and the latter reflects objectively the allowable conditions and feasibility. If "possibility" relevant quantitative value is defined as the possibility degree, achieve "demand" relevant quantitative definition as satisfiability degree, the quantitative value of the connection of possibility degree and satisfiability degree as possibility-satisfiability degree. And the corresponding method is called "possibility-satisfiability", namely P-S method. This method has been successfully used to discuss the population scale target, coal exploring scale, selecting location of new port and so on. Some practices have proved that this method be easy, have clear concept, relate to practice and can be expanded the application fields.
The two major concepts of P-S method are possibility degree and satisfiability degree. If something is sure to do, the highest possibility degree, the definition given for P (possibility), P = 1. If something won't be able to do, the lowest possibility degree, define P=0. So some real can indicate different level of possibility on [0, 1]. If something is entirely satisfactory, satisfability is the highest, defined as satisfiability (S), S = 1. If something is totally unacceptable, the lowest satisfaction, define S = 0. So some real can mean different level of satisfaction on [0, 1].
Suppose a thing, one attribute has a possibility-satisfiability curve, another attribute has a possibility-satisfiability curve , but ,and another attribute meet a relationship, ,then through a certain rule can be merged into one possibility-satisfiability curve with relative to the attribute, which is probably a quantitative description both possibility and satisfiability, ∈ [0, 1]. If, means a complete possibility and satisfiability; If , means a complete impossibility or dissatisfiability. So whenis real number and∈ [0, 1], it can express different possibility-satisfiability, using mathematical language as follows:
(1.1)
，
Thereinto, R、S、A indicate respectively admissible set (region) of attribute 、、,if the condition is both possibility and satisfiability, the possibility-satisfiability quantitative relationship of different attribute can be described as follows:
(1.2)
，
The specific operation generally has two ways: strong merger and weak merge. Strong merger means the combined possibility-satisfiability degree is strictly existence, using mathematical expression is as follows:
(1.3)
，
When，there is ， (1.4)
Weak merger means the combined possibility-satisfiability degree is maximum, using mathematical expression is as follows:
(1.5)
，
When，there is ， (1.6)
Through the different combined methods, we can draw many different possibility-satisfiability curves in different restriction conditions. Meanwhile, at the same coordinate, we can clearly see that the conditioned strength and trends of research object under the restricted factors, is to make the optimal choice.
P-S decision-making method provides the decision analysis tools of comprehensive considering many factors. It has the characteristics of integrating analysis with summary. P-S method's assignment is relatively liberal and flexible, which gives different base value with possibility-satisfiability adjustment and merger of different methods. So the sense of P-S method is not great in the short-term forecast, but this method can reflect the comprehensive effect of main and fundamental constraints, can play an important role in the long-term goal programming for research object.
1.2 "Possibility- satisfiability" algorithm
1.2.1 The mathematical form "Possibility- satisfiability" curve
According to definition of possibility-satisfiability degree, some mathematical form curves may express it, for instance three-broken line, S curve etc. Among, possibility degree P can be expressed by three-broken line as follows:
(1.7)
Fig. 1.1 The three-broken line of possibility
In addition to the three-broken line, and S curve is a commonly-used curve, and mathematical form are as follows：
(1.8)
Fig.1.2 The S-curve of possibility
The mathematical forms of satisfiability degree curves are similar, it unnecessary gives more details.
1.2.2 The merging algorithm of "Possibility- satisfiability"
As mentioned above, possibility-satisfiability curve is formed by merging possibility degree and satisfiability degree, which is divided into strong and weak merger. Meanwhile, when p(r), q(s) and f(r，s，α) are existent, the corresponding formula solution of possibility-satisfiability degree is available.
(1) If the limiting condition is (real numbers), p(r) and q(s) are three-broken lines, their weak merger solutions are as follows:
(1.9)
When p(r) and q(s) are S curves, their weak merger solutions are as follows:
(1.10)
(2) If the limiting condition is, p(r) and q(s) are three-broken lines, their weak merger solutions are as follows:
(1.11)
(3) If the limiting condition is p(r) and q(s) are three-broken lines, their weak merger solutions are as follows:
(1.12)
These mergers of different algorithms are applied to different programming problems, such as the study on population problem through yield of total and per capita is limited by . While the studying on yield through cultivated area and per unit area yield belongs to the second algorithm. This paper estimates the total energy consumption and emissions of carbon dioxide, which need compute across the population scale, the scale of economies, per capita consumption, the carbon emissions of per capita and per unit of output value. This study is limited by , so it belongs to the second algorithm.
(4) The merge method of two more possibility-satisfiability curves
After calculated many possibility-satisfiability curves, we need a comprehensive analysis when decision-making. In the merge of computation, the main consideration of three possibility-satisfiability of merger between curves, namely weak merger, strong merge and vary weighted sums.
Suppose we have two possibility-satisfiability curves w1、w2 that the merging algorithms are as follows:
(1) Weak merger
Symbol exception。
(1.13)
(2) Strong merge
Symbol or 。
(1.14)
(3) Vary weighted sums
Symbol
(1.15)
2. The multi-objective decision-making of carbon emissions
This paper uses the method of "P-S" to estimate China's carbon dioxide emission peak. While analyzing the emission of carbon, we should first resolve the factors that restrain the emission of carbon, then discuss them and through the "P-S" curve in different factors, we study them in the same coordinate system while carbon emission as the horizontal axis and "P-S" as vertical axis. Meanwhile, we can merge different "P-S" curves according to different theoretical assumptions and premises; finally we can get the optimal solution at the premise of different theoretical assumptions. Due to the diversity of merger way, this method can flexibly satisfy the decision-makers' special interests of considering different factors in a comprehensive compromise way while making a choice.
While we are making multi-objective plans in the use of P-S method, we should carefully consider the constraints into the model. Too much the factors will cause the complex of the model, increase the computation and increase the difficulty of parameter assignment data collection, too much constraint that is unimportant or have no constraint relation with analysis object will decrease the effect of main constraint factors. Less constraint can't comprehensively show the problem and will lose the original intention of P-S. Therefore, choose the main constraints into the model decide whether we will success. Choosing the suitable constraint factors will not only decrease the computation but also decrease subjective bias in the process of assigning parameters to excessive factors. So we should consider carefully while making a model and cancel those unnecessary constraints.
The satisfaction of carbon emission peak can be analyzed in two sides: one is indirect projections from the energy point of view, it means that we get the whole energy consume from per capita energy consumption and per unit output value energy consumption, then get the satisfactory of the whole carbon emission, the other is get satisfactory directly from per capita carbon emission, carbon emission intensity and carbon emission response to climate change.