2.3.1. Total Amount Change (T)

Total amount change T refers to the change of the total carbon emissions in a relevant section in the Sankey diagrams between different years. To a certain degree, total amount change reflects the change in the size of the industry's production capacity. The sectors with larger total amount change should be paid more attention for emission reduction, because improving the same energy efficiency or reducing the same carbon intensity in these sectors may lead to more emission reduction. The formula of the total amount change of sector *i* is as Equation (2):

$$\mathbf{T}\_{\bar{i}} = \mathbf{C}\_{T\bar{i}} - \mathbf{C}\_{t\bar{i}} \tag{2}$$

where *Cti* is the total carbon emissions of sector *i* in the base year *t*, *CTi* is the total carbon emissions of sector *i* in the observed year *T*.
