Table 1 Abbreviations in this paper
Abbreviations
|
Definition
|
CEEMDAN
|
Complete ensemble empirical mode decomposition with adaptive noise
|
GA
|
Genetic algorithm
|
ELM
|
Extreme learning machine
|
GA-ELM
|
Extreme learning machine optimized by genetic algorithm
|
GRA
|
Grey correlation analysis
|
PACF
|
Partial autocorrelation function
|
EMD
|
Empirical mode decomposition
|
EEMD
|
Ensemble empirical mode decomposition
|
IMF
|
Intrinsic mode function
|
BP
|
BP neural network optimized by particle swarm optimization algorithm
|
PSOBP
|
BP neural network optimized by particle swarm optimization algorithm optimized by particle swarm optimization algorithm
|
LSSVM
|
Least squares support vector machine
|
|
Goodness of fit
|
RMSE
|
Root mean square error
|
MAPE
|
Mean absolute percentage error
|
|
Common factor 1 extracted by Factor analysis
|
|
Common factor 1 extracted by Factor analysis
|
Table 2 Data sources
|
source
|
The carbon price
|
China Emissions Trading Website(http://www.tanpaifang.com/)
|
The price of coal
|
China zhengzhou Commodity Exchange(http://www.czce.com.cn/)
|
WTI crude oil prices
|
Yingwei Caiqing Financial Information Portal(https://cn.investing.com/)
|
Futures price of natural gas
|
Yingwei Caiqing Financial Information Portal(https://cn.investing.com/)
|
The exchange rate
|
Fred Economic Data(https://fred.stlouisfed.org/)
|
Carbon neutral
|
Baidu index(http://index.baidu.com/v2/index.html#/)
|
Carbon trading
|
Baidu index(http://index.baidu.com/v2/index.html#/)
|
Climate change,
|
Baidu index(http://index.baidu.com/v2/index.html#/)
|
Carbon footprint
|
Baidu index(http://index.baidu.com/v2/index.html#/)
|
Carbon sequestration
|
Baidu index(http://index.baidu.com/v2/index.html#/)
|
Table 3 Details of data from three carbon markets
Market
|
Beijing
|
Guangdong
|
Shanghai
|
Tape
|
BEA
|
GDEA
|
SHEA
|
Data
|
2019/1/9~2019/12/31
|
The case number
|
239
|
239
|
239
|
Mean standard error
|
0.63966
|
0.16971
|
0.26453
|
The standard deviation
|
9.88897
|
2.62364
|
4.08957
|
The variance
|
97.792
|
6.883
|
16.725
|
Range
|
39.10
|
10.11
|
20.68
|
The minimum value
|
48.40
|
17.90
|
27.32
|
The maximum
|
87.50
|
28.01
|
48.00
|
Table 4 Correlation analysis of 9 influencing factors of carbon price.
Influencing factors
|
The correlation
|
Influencing factors
|
The correlation
|
The exchange rate
|
0.9451
|
Climate change
|
0.8864
|
The price of coal
|
0.9407
|
Futures price of natural gas
|
0.8786
|
WTI crude oil prices
|
0.9364
|
Carbon trading
|
0.8618
|
Carbon sequestration
|
0.9065
|
Carbon neutral
|
0.7938
|
Carbon footprint
|
0.9038
|
|
|
Table 5 KMO and Bartlett test.
KMO
|
0.774
|
Bartlett sphericity test
|
Approximate chi-square
|
2460.058
|
Degree of freedom
|
10
|
Significance
|
0.000
|
Table 6 The results of factor analysis
Influencing factors
|
Variance of common factor
|
Component score coefficient
|
Cumulative contribution(%)
|
Factor 1
|
Factor 2
|
85.804
|
Climate change
|
0.864
|
-0.266
|
0.642
|
Carbon sequestration
|
0.861
|
0.230
|
0.166
|
Carbon trading
|
0.886
|
0.475
|
-0.189
|
Carbon neutral
|
0.875
|
0.469
|
-0.183
|
Carbon footprint
|
0.805
|
-0.053
|
0.459
|
Due to technical limitations, table 7 is only available as a download in the Supplemental Files section.
Table 8 Predictive effects of all models(Beijing)
The model number
|
|
|
|
|
1
|
BP
|
0.6883
|
5.9143
|
0.0687
|
2
|
LSSVM
|
0.7580
|
5.0571
|
0.0518
|
3
|
PSO-BP
|
0.7721
|
4.5694
|
0.0490
|
4
|
ELM
|
0.8139
|
4.3848
|
0.0442
|
5
|
GA-ELM
|
0.8428
|
4.1994
|
0.0402
|
6
|
EEMD-ELM
|
0.8543
|
4.1761
|
0.0486
|
7
|
EEMD-BP
|
0.9438
|
2.5927
|
0.0295
|
8
|
EEMD-PSO-BP
|
0.9636
|
2.1347
|
0.0248
|
9
|
EEMD-LSSVM
|
0.9796
|
1.5619
|
0.0177
|
10
|
EEMD-GA-ELM
|
0.9890
|
1.1473
|
0.0127
|
11
|
CEEMDAN-ELM
|
0.9074
|
3.4077
|
0.0347
|
12
|
CEEMDAN-BP
|
0.9503
|
2.4964
|
0.0274
|
13
|
CEEMDAN-PSO-BP
|
0.9759
|
1.6993
|
0.0179
|
14
|
CEEMDAN-LSSVM
|
0.9831
|
1.4568
|
0.0169
|
15
|
CEEMDAN-GA-ELM
|
0.9898
|
1.1294
|
0.0120
|
Table 9 Predictive effects of all models(Shanghai and Guangdong)
Model
|
Shanghai
|
Guangdong
|
|
|
|
|
|
|
EEMD-ELM
|
0.7566
|
1.2301
|
0.0240
|
0.6615
|
0.2673
|
0.0082
|
EEMD-BP
|
0.9254
|
0.6811
|
0.0113
|
0.7507
|
0.2286
|
0.0073
|
EEMD-PSO-BP
|
0.9301
|
0.6594
|
0.6594
|
0.7796
|
0.2149
|
0.0058
|
EEMD-LSSVM
|
0.9342
|
0.6240
|
0.0109
|
0.8661
|
0.1675
|
0.0052
|
EEMD-GA-ELM
|
0.9387
|
0.6175
|
0.0100
|
0.8568
|
0.1739
|
0.0053
|
CEEMDAN-ELM
|
0.8420
|
0.9901
|
0.0171
|
0.8807
|
0.1581
|
0.0050
|
CEEMDAN-BP
|
0.8916
|
0.8201
|
0.0149
|
0.8813
|
0.1583
|
0.0049
|
CEEMDAN-PSO-BP
|
0.8969
|
0.7998
|
0.0138
|
0.9157
|
0.1329
|
0.0039
|
CEEMDAN-LSSVM
|
0.9221
|
0.6951
|
0.0116
|
0.9230
|
0.1274
|
0.0039
|
CEEMDAN-GA-ELM
|
0.9468
|
0.5748
|
0.0099
|
0.9465
|
0.1062
|
0.0032
|