From reference to reality: Methods for explaining emission trends

Figures & data

Figure 1. Electricity production by source 1990 – 2000 (in PJ of electricity).

Figure 2. CO₂ emissions by energy source (in Mton).

Figure 3. CO₂ emissions per fuel from 1990 to 2000.

Figure 4. Trend in electric efficiency of the central power stations.

Table I. Effect of various measures on CO₂ emissions (2000 vs 1990, in Mton) under the composition method.

Sequence 1 (Mton of CO2)		Sequence 2 (Mton of CO2)
Change in fuel mix	2.2	Increase in imports	−6.0
Efficiency improvement	−2.6	Growth in CHP	−6.1
Increase in renewables	−1.2	Increase in renewables	−1.2
Growth in CHP	−6.2	Efficiency improvement	−4.1
Increase in imports	−6.1	Change in fuel mix	1.5
Total	−13.8	Total	−15.9

Table II. Effect of various measures on CO₂ emissions (2000 vs 1990, in Mton) under the decomposition method.

Environmental Balance sequence (Mton of CO2)		Policies sequence 3 (Mton of CO2)
Increase in imports	−4.4	Increase in imports	−4.4
Growth in CHP	−5.4	Change in fuel mix	3.4
Increase in renewables	−1.1	Efficiency improvement	−1.0
Efficiency improvement	−2.7	Growth in CHP	−4.4
Change in fuel mix	2.3	Increase in renewables	−1.0
Total	−11.2	Total	−10.4

Table III. Comparison of various methods for calculating CO₂ emission reductions in 2000 compared with 1990.

	Method (Mton of CO2)
	Individual effects		Composition		Decomposition
Effects	Reference CCGT	Reference average central power stations	Sequence 1	Sequence 2	Balance Environmental sequence	Policies sequence
Imports	−3.6	−6.0	−6.1	−6.0	−4.4	−4.4
CHP	−1.6	−6.1	−6.2	−6.1	−5.4	−4.4
Renewables	−0.7	−1.2	−1.2	−1.2	−1.1	−1.0
Efficiency improvements central	−2.8	−2.8	−2.6	−4.1	−2.7	−3.9
Fuel mix central power stations	2.2	2.2	2.2	1.5	2.3	3.4
Total	−6.5	−13.9	−13.8	−15.9	−11.2	−10.4