Table 5 M&C on high carbon energy intensity from 2021 to 2030 (10,000 tons of standard coal/100 million yuan, base period was 2011).

Year

Exponential model(M1)

\(y_{t} = y_{0} e^{at}\), a = ln(0.73)/9

\(y_{t} = y_{0} \lambda^{t}\),\(\lambda = 0.73^{1/9}\)

Difference model(M2)

\(y_{t} = (1{ - }\phi )^{{\text{t}}} (y_{0} - \mathop y\limits^{ \wedge } ) + \mathop y\limits^{ \wedge }\), \(\mathop y\limits^{ \wedge }\) = 0.7*\(y_{0}\),\(\phi = 1 - 0.1^{1/9}\)

Linear model(M3)

\(y_{t} = y_{0} + bt\)

b = −0.27*\(y_{0}\)/9;

Period overall objective