Estimation of what the factor should be:
The estimation is based on the CO2 emissions from fossil fuels of the year 2004. See Wikipedia, CO2 emissions and Wikipedia, CO2 emissions per capita.
Note: there are not enough detailed data (on a reasonable level of accuracy) available for the year 1990 to base the calculation on.
The general consensus is that the world population will grow from 6.400 million in 2004 to just above 9.300 million in 2050 (it has stabilised then). See Wikipedia, world population. This leads to P = 1,45.
The calculation of W is provided in Excel file “efficiency factor“. The following assumptions have been made:
– allocate to e everybody in the world an equal share of 8,5 ton/year CO2 emission per capita (8,5 is the current level of West European countries)
– this allows a fare share of wealth for everybody (Best Practices in production are assumed in all countries)
– the wealth is stabilised at the current level of the West European countries (there is no extra growth of wealth in Western Europe)
Under these assumptions W = 2,0 (note that this factor is caused by the fact that more people share the same wealth)
The assumption that 60% CO2 reduction (compared to the level in 2004) is sufficient to stop global warming, results in EB = 1/2,5.
The resulting efficiency EE follows from:
1/2,5 = 1,45 x 2 x 1/7,25
This means that the eco-efficiency should be improved by a Factor 7,25 on a world wide basis
Note that this factor is different for every country (see the Excel file “efficiency factor”)